Detection and treatment of cancer

ABSTRACT

The present invention relates to a method for diagnosing, evaluating the prognosis of a cancer patient and evaluating the aggressiveness of a cancer. The methods comprise detecting the phosphorylation status of a Scribble protein, a fragment or variant thereof, wherein the phosphorylation status is indicative of cancer, prognosis and the aggressiveness of a cancer. In one embodiment the cancer is breast cancer.

This application is a continuation application of U.S. patentapplication Ser. No. 14/055,396, filed on Oct. 16, 2013, the entiredisclosures of which is incorporated herein by reference.

FIELD OF THE INVENTION

The present invention relates to a prognostic biomarker and the use ofthe biomarker in methods for diagnosing, evaluating the prognosis andstaging cancer in a patient. Also within the scope of the invention arekits and methods for the treatment of cancer.

BACKGROUND OF THE INVENTION

Worldwide, breast cancer is the second most common type of cancer andone of the most common causes of cancer death in humans. It is the mostcommon cancer in women. Breast cancer is a heterogeneous disease that istreated by surgery, chemotherapy and several rationale-based targetedtherapies. The choice of optimal course of treatment depends on theavailability of biomarkers, which are measured by appropriate clinicalassays. Unfortunately, at the present very few useful biomarkers havebeen identified and translated to clinical use. These are the oestrogenreceptor (ER), progesterone receptor (PR) and the ErbB2 receptor. Thesethree markers are very useful but about a third of diagnosed cases aretriple-negative. In other words, the tumours do not express ER, PgR andHer2. For this type of breast cancer new biomarkers and diagnostic andprognostic assays are in high demand.

Cancer metastasis is a multistage process that is governed by a complexprogram of gene expression and signal transduction that ultimatelyallows the metastasizing cells to invade surrounding stroma, travelthrough the circulation, and colonize distant sites. This programsequentially switches specific genes on and turns others off,effectively exerting very dramatic changes of the abundance of manyhundreds of proteins in the cell. Since the completion of the humangenome project, post-genomic approaches based on application ofoligonucleotide microarrays and next-generation sequencing are beginningto shed light on the global cancer genomics landscape and its molecularlandmarks.

In addition, developments in quantitative proteomics now allow us to digeven deeper: to map the posttranslational modifications andprotein-protein interactions that are at the core of the regulation ofthe molecular mechanisms that drive metastasis. Here I describe one suchquantitative proteomics approach to investigate the role of CD74 inpromoting metastasis of triple-negative breast cancer, a particularlymalignant type of the disease.

CD74, the γ subunit of the major histocompatibility complex (MHC) classII complex, is frequently overexpressed in malignant tumors ofepithelial and mesenchymal origin. The protein has been suggested as apotential target for rationale-based therapies of lymphoma and multiplemyeloma and therapeutic agents targeting CD74 or components of itssignaling cascade are in advanced stages of clinical development [1-3].More recently, I and others reported that CD74 overexpression is linkedto increased invasion and metastasis of breast tumors, particularly thetumors of the triple-negative phenotype [4,5]. CD74 is a chaperoneprotein with an important role in innate immunity. It is required forthe expression and functions of the MHC class II receptors and, inaddition, has been implicated in cytokine and survival signaling [6-8].However, the mechanistic foundation for the apparent CD74-augmentedmalignancy of triple-negative breast tumors is not known. To addressthis, I have engineered human epithelial cells to express CD74 under thecontrol of a highly regulated inducible promoter, which allowed us tostudy the effect of CD74 overexpression on protein abundance and proteinphosphorylation at a system-wide scale.

I have surprisingly identified that when overexpressed, CD74 affects thephosphorylation state and function of Scribble, a product of thewell-known tumor suppressor gene scrib, which is crucial for the propermaintenance of epithelial cell integrity and function and which isfrequently deregulated in breast cancer [9]. Scribble function inmaintaining polarity was first discovered in Drosophila. Bilder et al.found that scrib mutations cause aberrant cell shape and loss ofmonolayer organization in epithelia [10] and that scrib acts as a tumorsuppressor [11]. In human cells, Scribble is required forE-cadherin-mediated cell-cell adhesion, and when its expression isdownregulated, epithelial cells acquire mesenchymal appearance and theirmigration is augmented [12].

The invention is aimed at providing methods for the detection andprognosis of cancer, in particular epithelial cancer.

SUMMARY OF THE INVENTION

In the present invention I describe a new prognostic biomarker:Scribble. Accordingly, a first aspect of the present invention providesa method of diagnosing cancer in a patient, the method comprisingdetecting the phosphorylation status of a Scribble protein, a fragmentor variant thereof, wherein said phosphorylation status is indicative ofcancer.

In a second aspect of the invention I provide a method of detectingcancer metastasis in a patient, the method comprising detecting thephosphorylation status of a Scribble protein, a fragment or variantthereof, wherein the phosphorylation status is indicative of metastasis.

In a third aspect of the invention I provide a method for evaluating theprognosis of cancer, the method comprising detecting the phosphorylationstatus of a Scribble protein, a fragment or variant thereof, wherein thephosphorylation status is indicative of prognosis. Thus, the presentmethod permits the differentiation of cancer patients with a goodprognosis (i.e. disease-free survival) from those patients with a badprognosis.

In a fourth aspect of the invention I provide a method of selecting atreatment for cancer, the method comprising detecting thephosphorylation status of a Scribble protein, a fragment or variantthereof and selecting a treatment depending on said phosphorylationstatus.

In a fifth aspect of the invention I provide a method of selecting asubject for the treatment of cancer, the method comprising detecting thephosphorylation status of a Scribble protein, a fragment or variantthereof and selecting a subject depending on said phosphorylationstatus.

In a further aspect of the invention I provide a method for detectingthe phosphorylation status of a Scribble protein with SEQ ID NO: 1, afragment or variant thereof, the method comprising:

obtaining a sample from a patient and contacting the sample with atleast one antibody that is capable of specifically bindingphosphorylated or unphosphorylated residues S1306, S1309, S1348 andS1448 or a combination thereof in the Scribble protein, fragment orvariant thereof. In one embodiment, the method is performed inconjunction with at least one of the following: evaluating cancerprognosis, developing a cancer treatment plan, assessing the efficiencyof cancer treatment and the likelihood of metastases.

In a further aspect of the invention I provide a method for monitoringthe effectiveness of a treatment, the method comprising detecting thephosphorylation status of a Scribble protein, a fragment or variantthereof, and determining effectiveness of a treatment.

The present invention also contemplates the assessment of thephosphorylation status of the Scribble protein, a fragment or variantthereof, where the phosphorylation status indicates an increasedaggressiveness (e.g. metastatic potential) of the cancer tumor. As such,the phosphorylation status of the Scribble protein serves as a predictorof disease status and stage. The invention therefore relates to methodsfor assessing the aggressiveness of a tumor comprising assessing thephosphorylation status of the Scribble protein, a fragment or variantthereof.

In another aspect, the invention provides a method for monitoringdisease progression comprising assessing the phosphorylation status ofthe Scribble protein, a fragment or variant thereof. For example,changes in the patient's condition can be monitored by comparing changesin the phosphorylation status of the Scribble protein, a fragment orvariant thereof in the patient over time. Progressive decreases in thephosphorylation status of the Scribble protein, a fragment or variantthereof are indicative of increased potential for tumor invasion andmetastasis.

In one embodiment of any of the above methods described herein, themethod comprises detecting the phosphorylation status of one or moreresidues of a Scribble protein, fragment or variant thereof. In apreferred embodiment, the method comprises detecting the phosphorylationstatus of at least one of the following residues S1306, S1309, S1348 andS1448 or a combination thereof. In a further preferred embodiment themethod comprises detecting the phosphorylation of no other residues thanS1306, S1309, S1348 and S1448.

In one embodiment of the methods described herein, the cancer isepithelial cancer. In a preferred embodiment, the cancer is breast,pancreas, bone, liver, stomach, lung (for example non-small cell lungcancer (NSCLC)), colorectal, bladder, prostate, head and neck cancer orovarian cancer. In a more preferred embodiment, the cancer is breastcancer and the breast cancer tumour does not express at least one markerselected from the group consisting of oestrogen receptor (ER),progesterone receptor (PgR) and the ErbB2 receptor. This is known astriple negative breast cancer.

In a further embodiment of the methods described herein, detecting thephosphorylation status comprises obtaining a sample from said patientand contacting the sample with at least one antibody that is capable ofspecifically binding phosphorylated residues of a Scribble protein,fragment or variant thereof. In an alternative embodiment, detecting thephosphorylation status comprises obtaining a sample from said patientand detecting the phosphorylation status by mass spectrometry. In afurther embodiment, the method comprises detecting the expression of oneor more other biomarkers. In a further embodiment this can comprisedetecting the expression levels of the Scribble protein, or a fragmentor variant thereof. The methods further comprise comparing thephosphorylation status of Scribble in the patient's test sample with thephosphorylation status of Scribble in a control or reference sample.

In one embodiment of the methods described herein, the patient has or isat risk of developing cancer. In an alternative embodiment the patienthas no clinical signs or manifestations of cancer (i.e. the patient isasymptomatic). In a preferred embodiment, the patient is a humanpatient.

In an additional embodiment of the methods described herein, the methodcomprises detecting the phosphorylation status, and preferably measuringthe concentration of at least one of the phosphorylated peptides fromTable 1, preferably using mass spectrometry or antibodies. In apreferred embodiment the phosphopeptides are measured by massspectrometry using internal standards having the same amino acidsequence and posttranslational modifications but labelled with stableisotopes.

In one embodiment, the subject invention does not comprise the step ofdetermining Scribble expression level in the subject's sample.

In a further aspect of the invention there is provided a kit. In apreferred embodiment the kit is suitable for implementing any of theabove described methods. In one embodiment the kit comprises at leastone antibody, wherein the or each of said antibody is capable of bindingto at least one phosphorylated or unphosphorylated residue in a Scribbleprotein, or fragment or variant thereof, selected from S1306, S1309,S1348 and S1448 or a combination thereof. In a preferred embodiment thekit comprises agents for the detection of the at least one antibodybinding to said phosphorylated residues in Scribble. In a furtherembodiment the kit comprises instructions for use. In a furtherembodiment the kit comprises a positive control sample.

In a further aspect of the invention there is provided an antibodycapable of selectively binding to at least one phosphorylated residue ina Scribble protein, or fragment or variant thereof, wherein said residueis selected from S1306, S1309, S1348 and S1448 or a combination thereof.In an alternative aspect of the invention there is provided an antibodycapable of selectively binding to at least one unphosphorylated residuein a Scribble protein, or fragment or variant thereof, wherein saidresidue is selected from S1306, S1309, S1348 and S1448 or a combinationthereof.

In a another aspect of the invention there is provided a method oftreating cancer, the method comprising administering an agent capable ofphosphorylating or preventing the dephosphorylation of a Scribbleprotein, or fragment or variant thereof. In one embodiment, the agent iscapable of phosphorylating or preventing the dephosphorylation of atleast one residue in a Scribble protein, fragment or variant thereof,wherein said residue is selected from S1306, S1309, S1348 and S1448 or acombination thereof.

In a final aspect of the invention there is provided a pharmaceuticalcomposition comprising an agent capable of phosphorylating or preventingthe dephosphorylation of at least one residue in a Scribble protein,fragment or variant thereof, wherein said residue is selected fromS1306, S1309, S1348 and S1448 or a combination thereof, and apharmaceutically acceptable carrier.

DESCRIPTION OF THE FIGURES

The invention is further described in the following non-limitingfigures.

FIG. 1 shows the effect of CD74 overexpression on the pattern ofposttranslational modifications of the tumour suppressor proteinScribble.

CD74 overexpression affects the pattern of posttranslationalmodifications of the tumor suppressor protein Scribble. (FIG. 1.A)Domain map of Scribble based on a cartoon from the SMART databaseshowing the four phosphorylation hotspots in the C-terminal part of theprotein affected by CD74 overexpression in HEK293 and MCF7 cells. Thethree sites were identified in quantitative proteomics/phosphoproteomicsscreens using transiently transfected MCF7 and HEK293 cells and stablytransfected HEK293s cells expressing CD74 under the control oftetracycline-inducible promoter. (FIG. 1.B) Scatterplot of Scribblephosphopeptides detected by high-resolution LC-MS/MS analysis. Thenormalized heavy-to-light ratios are plotted against the Andromedascore. Two clusters of data points are apparent: a set ofphosphopeptides that center around H/L ratio of 1, which are notaffected by CD74 overexpression, and another cluster that contains thephosphopeptides that are strongly decreased in the CD74-overexpressingcells. The P value was calculated by the Student's t test using thenormalized H/L ratios of the two clusters indicated by grey borders.(FIG. 1.C) Zoom-in of the isotope envelops of two phosphopeptide ionsshowing large difference between the intensities of the light peptideions and the heavy counterparts deriving from CD74-overexpressing cells.The phosphopeptide sequences are indicated under the spectra.

FIG. 2 shows Scribble mislocalisation in CD74-overexpressing cells.Laser scanning confocal images of control (FIG. 2.A and FIG. 2.C) andtransfected (FIG. 2.B and FIG. 2.D) MCF7 (FIG. 2.A and FIG. 2.B) andHEK293 (FIG. 2.C and FIG. 2.D) cells stained with mouse monoclonalanti-Scribble primary antibodies and anti-mouse fluoresceinisothiocyanate conjugate. Representative focal planes taken from themidsection of the cells are shown.

FIG. 3 shows Scribble expression in stably transfected HEK293s cellsexpressing CD74 under the control of tetracycline-inducible promoter.(FIG. 3.A) Western blot analysis showing the same Scribble abundance inthe fully denatured and unfolded samples extracted from control andtetracycline-induced cells. (FIG. 3.B) The same cell cultures as in Ashow increased Scribble staining in the CD74-overexpressing cells inFACS assays despite the fact that the same anti-Scribble primaryantibody is used. The filled-in gray histogram is from secondaryantibody-only control. (FIG. 3.C) The same cell cultures as in FIG. 3.Aand FIG. 3.B show increased Scribble staining by confocal microscopy.The same primary antibody is used.

FIG. 4 shows Scribble and CD74 copurified from membrane protein isolatesand colocalize in stably transfected HEK293s cells. (FIG. 4.A)Co-IP/Western blot analysis. Scribble is detected only in the CD74 IPfrom cells induced with tetracycline to express CD74. (FIG. 4.B)Co-IP/MS. The multiple reaction monitoring (MRM) signal for the reporterpeptides is normalized to 100. The values are mean of three replicateLC-MS/MS analyses±SD. This experiment was performed twice. First, CD74expression was induced in the heavy SILAC-labeled cells. Then, theprotein was overexpressed in the light SILAC-labeled cells. In bothexperiments, MaxQuant detected Scribble peptides only in the CD74 IPfrom tetracycline-induced cells. (FIG. 4.C) Colocalization of Scribbleand CD74 in HEK293s cells overexpressing CD74.

FIG. 5 shows that overexpression of CD74 induces translocation of asubpopulation of Scribble molecules from the basolateral side to theapical side of the cells. GFP-Scribble was transiently transfected inTetO-CD74 HEK293s cells and the expression of CD74 was induced withtetracycline. After 24 hours of induction, the cells were fixed andstained with anti-CD74 antibody and analyzed by laser scanning confocalmicroscopy. The Figure shows CD34 expression in uninduced (FIG. 5.A) andtetracycline-induced (FIG. 5.B) cells. The images are presented as“Slice Views,” in which the three orthogonal planes XY (the midsectionof the stack), YZ, and XZ are formed by slicing the stack as indicatedby the crossed orange lines. The white arrows point to the apical sideof the cells where GFP-Scribble can be seen only in the cellsoverexpressing CD74 (FIG. 5.A and 5.B).

FIG. 6 shows Overexpression of CD74 in lymph node-metastatictriple-negative breast tumors. (Top) Formaldehyde-fixed section from atumor was stained with secondary antibody only (FIG. 6.A); CD74 stainingin a section from node-negative tumor showing positive staining ininfiltrating lymphocytes and negative malignant cells (FIG. 6.B); CD74staining in a node-positive triple-negative tumor showing strongcytoplasmic staining of the malignant cells (FIG. 6.C). FIG. 6.D showsthat CD74 IHC scores for node-positive (n=9) and node-negative (n=10)tumors. The mean and SEM are indicated by horizontal lines. The P valueof 0.0409 was calculated by one-tailed nonparametric Mann-Whitney ttest. A one-tailed Fisher's exact test assuming cut value of 5 returns aP value of 0.051. FIG. 6.E shows that CD74 and Scribble abundances inthe membrane fractions of cultured breast cancer cell lines and theHEK293s cell line. The abundance was estimated by the spectral countmethod in triplicate LC-MS/MS analyses. CD74 spectral counts are plottedon the right y-axis. The protein was only detected in MDA-435-MB.Scribble spectral counts are plotted on left y-axis. Vertical barsrepresent SDs. Only MS/MS spectra passing the 1% FDR threshold ascalculated by MaxQuant were included in the analysis. Scribble is barelydetectable with one to two spectral counts in MDA-435-MB.

FIG. 7 shows CD74 knockdown affects the wound healing in MDA-435-MB.(FIG. 7.A) Western blot analysis of CD74 abundance in cells transfectedwith control DNA (left) and CD74 siRNA performed 18 hours aftertransfection. (FIG. 7.B) Bar graph is based on two replicate analyses.(FIG. 7.C and FIG. 7.D) Wound healing assay with control (FIG. 7.C) andCD74 (FIG. 7.D) siRNA-transfected cells. The assays were started 18hours after transfection. Photographs were taken at 0, 16, and 30 hours.

FIG. 8 shows (FIG. 8.A) Scribble peptides and phosphorylation sitesdetected in immunoprecipitated Scribble by high-resolution massspectrometry. The detected peptides are shown as boxed sequenceshighlighted in yellow. The three phosphopeptides affected by CD74overexpression are highlighted in blue with phosphoserines shown in red.(FIG. 8.B) Measured H/L ratios for the high-scoring Scribble peptides(Andromeda score>100) showing that the unmodified peptides center on anormalized H/L ratio of 1 (blue symbols). The three phosphorylatedpeptides, shown with red symbols±SD, are significantly decreased in theheavy Scribble molecules coming from CD74-overexpressing cells. For eachof the phosphopeptides, the Student's two-tailed t test returns a Pvalue that is lower than 0.0001 when calculated against the normalizedH/L ratios of the unmodified peptides shown with blue triangles.

FIG. 9 shows that long-term overexpression of CD74 leads to a decreaseof Scribble abundance as determined by Western blot analysis. (FIG. 9.A)Scribble detection in lysates from uninduced TetR/TetO-CD74 cells andcells induced with tetracycline for 48 hours. (FIG. 9.B) Bar graph ofthe integrated band intensities of Scribble determined by the infraredfluorescent scanner in two independent experiments. The intensities werenormalized against tubulin.

FIG. 10 shows label-free quantitation (LFQ) of CD74 and Scribble inmembrane isolates of 25 breast tumor biopsies. The membrane proteinswere isolated by the permeabilization and extraction procedure, digestedwith trypsin, and analyzed by LC-MS/MS as described in Materials andMethods section. MaxQuant was used to process the LC-MS/MS data andcalculate LFQ as described in [28]. The nonparametric Spearman p andcorresponding P values were calculated in R using cor.test.

FIG. 11 shows the detection of phosphorylated peptideQSPAS(ph)PPPLGGGAPVR (SEQ ID NO: 15) derived from human Scribbleexpressed in HEK293 cells as a GFP-tagged recombinant protein. Scribblewas immunoprecipitated using a monoclonal anti-GFP antibody, digestedwith trypsin and analyzed by nano-scale LC-MS/MS. The phosphorylationsites was mapped to the serine residue at position 5 and is indicatedwith (ph) after the acceptor residue. The top trace (FIG. 11.A) is totalion chromatogram (TIC). Below (FIG. 11.B) is the base peak chromatogramtrace in red. The phosphorylated peptide is detected as doubly-chargedion with a mass to charge ratio of 784.385. The extracted ionchromatogram for this eptide is shown as a blue trace. The isotopiccluster of this peptide ion is shown in the zoomed in high-resolutionspectrum on the bottom. The unphosphorylated peptide was also detectedas a doubly-charged ion with m/z of 744.402. Its extracted ionchromatogram is shown with a green trace and spectrum in the insertframed in blue.

DETAILED DESCRIPTION OF THE INVENTION

The present invention will now be further described. In the followingpassages, different aspects of the invention are defined in more detail.Each aspect so defined may be combined with any other aspect or aspectsunless clearly indicated to the contrary. In particular, any featureindicated as being preferred or advantageous may be combined with anyother feature or features being indicated as being preferred oradvantageous.

The inventor has surprisingly shown that when overexpressed, CD74affects the phosphorylation state, localisation and hence function ofScribble, a product of the well-known tumor suppressor gene SCRIB. SCRIBis crucial for the proper maintenance of epithelial cell integrity andfunction and is frequently deregulated in breast cancer. Furthermore,using epithelial cell lines expressing CD74 under the control oftetracycline-inducible promoter and quantitative high-resolution massspectrometry, I demonstrate that, as a result of CD74 overexpression,the phosphorylation pattern of the C-terminal part of Scribble undergoesspecific changes. This is accompanied with a translocation of theprotein from the sites of cell-to-cell contacts at the plasma membraneto the cytoplasm, which is likely to effectively enhance the motilityand invasiveness of the cancer cells. Accordingly, the inventordescribes a new prognostic biomarker, Scribble.

The term ‘Scribble protein’ refers to the protein encoded by SCRIB(scribbled planar cell polarity protein) and represented by SEQ ID NO:1.

SEQ ID NO: 1:    1mlkciplwrc nrhvesvdkr hcslqavpee iyrysrslee llldanqlre lpkpffrlln   61lrklglsdne iqrlppevan fmqlveldvs rndipeipes ikfckaleia dfsgnplsrl  121pdgftqlrsl ahlalndvsl qalpgdvgnl anlvtlelre nllkslpasl sflvkleqld  181lggndlevlp dtlgalpnlr elwldrnqls alppelgnlr rlvcldvsen rleelpaelg  241glvlltdlll sqnllrrlpd gigqlkqlsi lkvdqnrlce vteaigdcen lseliltenl  301lmalprslgk ltkltnlnvd rnhlealppe iggcvalsvl slrdnrlavl ppelahttel  361hvldvagnrl qslpfalthl nlkalwlaen qaqpmlrfqt eddartgekv ltcyllpqqp  421plsledagqq gslsetwsda ppsrvsviqf leapigdeda eeaaaekrgl qrratphpse  481lkvmkrsieg rrseacpcqp dsgsplpaee ekrlsaesgl sedsrpsast vseaepegps  541aeaqggsqqe attaggeeda eedyqeptvh faedallpgd dreieegqpe apwtlpggrq  601rlirkdtphy kkhfkisklp qpeavvallq gmqpdgegpv apggwhngph apwapraqke  661eeeeeegspq eeeeeeeeen raeeeeaste eedkegavvs apsvkgvsfd qannlliepa  721rieeeeltlt ilrqtgglgi siaggkgstp ykgddegifi srvseegpaa ragvrvgdkl  781levngvalqg aehheaveal rgagtavqmr vwrermvepe navtitplrp eddysprerr  841ggglrlpllp pespgplrqr hvaclarser glgfsiaggk gstpyragda gifvsriaeg  901gaahragtlq vgdrvlsing vdvtearhdh avslltaasp tialllerea ggplppsplp  961hsspptaava ttsittatpg vpglpslaps llaaalegpy pveeirlpra ggplglsivg 1021gsdhsshpfg vqepgvfisk vlprglaars glrvgdrila vngqdvrdat hqeaysallr 1081pclelsllvr rdpappglre lciqkapger lgisirggar ghagnprdpt degifiskvs 1141ptgaagrdgr lrvglrllev nqqsllglth geavqllrsv gdtltvlvcd gfeastdaal 1201evspgvianp faagighrns lesissidre lspegpgkek elpgqtlhwg peateaagrg 1261lqplkldyra laavpsagsv qrvpsgaagg kmaespcsps gqqppsppsp delpanvkqa 1321yrafaavpts hppedapaqp ptpgpaaspe qlsfrerqky felevrvpqa egppkrvslv 1381gaddlrkmqe eearklqqkr aqmlreaaea gaearlaldg etlgeeeqed eqppwaspsp 1441tsrqspaspp plgggapvrt akaerrhqer lrvqspeppa peralspakl raleaekral 1501wraarmksle gdalraqmvl srsqegrgtr gplerlaeap spaptpsptp vedlgpqtst 1561spgrlspdfa eelrslepsp spgpqeedge valvllgrps pgavgpedva lcssrrpvrp 1621grrglgpvps

The nucleic acid sequence encoding Scribble (NG 030583.1) isincorporated herein by reference.

The term ‘a Scribble protein’ also encompasses all alternatively splicedisoforms. The term also encompasses all fragments and variants thereof.

The term ‘fragment’ refers to a portion of the amino acid sequence thatis less than the complete length and includes at least a minimum lengthcapable of maintaining the biological properties required in the presentinvention. In a preferred embodiment the fragment is between residues1295 and 1448 inclusive. In a further preferred embodiment the fragmentis between residues 1306 and 1448 inclusive. In a further preferredembodiment the fragment is between 13006 and 1348 inclusive.

The term ‘variant’ refers to the protein sequence where the amino acidsare substantially identical to SEQ ID NO: 1. A variant retains thebiological function and activity of the Scribble protein. The variantmay be achieved by modifications such as insertion, substitution ordeletion of one or more of the amino acids. In a preferred embodiment,the variant thereof has at least 50%, at least 55%, at least 60%, atleast 65%, at least 70%, at least 75%, at least 80%, at least 85%, atleast 90%, at least 91%, at least 92%, at least 93%, at least 94%, atleast 95%, at least 96%, at least 97%, at least 98%, at least 99%identity to SEQ ID NO:1.

A cancer is an example of a proliferative disorder. Cells characteristicof proliferative disorders (i.e., “neoplastic cells” or “tumor cells”)have the capacity for autonomous growth, i.e., an abnormal state orcondition characterized by inappropriate proliferative growth of cellpopulations. A neoplastic cell or a tumor cell is a cell thatproliferates at an abnormally high rate. A new growth comprisingneoplastic cells is a neoplasm, also known as a “tumor.” A tumor is anabnormal tissue growth, generally forming a distinct mass that grows bycellular proliferation more rapidly than normal tissue. A tumor may showa partial or total lack of structural organization and functionalcoordination with normal tissue. As used herein, a tumor is intended toencompass hematopoietic tumors as well as solid tumors.

A tumor may be benign (benign tumor) or malignant (malignant tumor orcancer). Malignant tumors can be broadly classified into three majortypes. Malignant tumors arising from epithelial structures are calledcarcinomas; malignant tumors that originate from connective tissues suchas muscle, cartilage, fat, or bone are called sarcomas; and malignanttumors affecting hematopoietic structures (structures pertaining to theformation of blood cells) including components of the immune system arecalled leukemias and lymphomas, Ewing's sarcomas, osteosarcomas, andchondrosarcomas.

The methods described herein are particularly relevant for the treatmentof humans having an epithelial malignancy. Epithelial malignancies arecancers that affect epithelial tissues, such as a lung cancer (e.g.,non-small-cell lung cancer (NSCLC)), breast cancer, colorectal cancer,head and neck cancer, prostate or ovarian cancer. In a preferredembodiment, the cancer is breast cancer.

The term ‘breast cancer’ refers to those conditions classified by biopsyas malignant pathology. The clinical delineation of breast cancerdiagnoses is well-known in the medical arts. One of skill in the artwill appreciate that breast cancer refers to any malignancy of thebreast tissue, including, for example, carcinomas and sarcomas. Inparticular embodiments, the breast cancer is ductal carcinoma in situ(DCIS), lobular carcinoma in situ (LCIS), or mucinous carcinoma. Breastcancer also refers to infiltrating ductal (IDC) or infiltrating lobularcarcinoma (ILC). In most embodiments of the invention, the subject ofinterest is a human patient suspected of or actually diagnosed withbreast cancer.

The term ‘staging’ refers to the stage of cancer, and can be defined inone example by reference to the American Joint Committee on Cancer(AJCC), which has developed a standardized system for breast cancerstaging using a “TNM” classification scheme. Patients are assessed forprimary tumour size (T), regional lymph node status (N), and thepresence/absence of distant metastasis (M) and then classified intostages 0-IV based on this combination of factors. In this system,primary tumour size is categorized on a scale of 0-4 (T0=no evidence ofprimary tumour; T1=<=2 cm; T2=>2 cm-<5 cm; T3=>5 cm; T4=tumour of anysize with direct spread to chest wall or skin). Lymph node status isclassified as N0-N3 (N0=regional lymph nodes are free of metastasis;N1=metastasis to movable, same-side axillary lymph node(s);N2=metastasis to same-side lymph node(s) fixed to one another or toother structures; N3=metastasis to same-side lymph nodes beneath thebreastbone). Metastasis is categorized by the absence (M0) or presenceof distant metastases (M1).

Methods of identifying breast cancer patients and staging the diseaseare well known and may include manual examination, biopsy, review ofpatient's and/or family history, and imaging techniques, such asmammography, magnetic resonance imaging (MRI), and positron emissiontomography (PET).

A “subject” as described herein can be any subject having aproliferative disorder. For example, the subject can be any mammal, suchas a human, including a human cancer patient. Exemplary nonhuman mammalsinclude a nonhuman primate (such as a monkey or ape) and a rodent, suchas mouse or rat.

Accordingly, the invention relates to method of diagnosing cancer in apatient, the method comprising detecting the phosphorylation status of aScribble protein, a fragment or variant thereof, wherein saidphosphorylation status is indicative of cancer. In a preferredembodiment the method comprises detecting the phosphorylation status ofone or more residues of a Scribble protein or fragment or variantthereof.

In another aspect the invention relates to a method of detecting cancermetastasis in a patient, the method comprising detecting thephosphorylation status of a Scribble protein, a fragment or variantthereof, wherein the phosphorylation status is indicative of metastasis.

The term ‘metastasis’ refers to a complex series of steps in whichneoplasic cells leave the original tumor site and migrate to other partsof the body via the blood stream or the lymphatic system and start newtumors that resemble the primary tumor. Breast cancer cells are oftentransported through the lymphatic pathway to bone or other areas such asliver, lung or brain. It may be crucial to the survival of the patientto predict whether a primary cancer has the potential to metastasizesuch that high risk patients can be subject to closer follow up orspecific treatment regime that will vary where the cancer hasmetastasized. Currently there is no way to visualize metastatic tumorsso that effectiveness of therapy can be more easily monitored.Currently, detection of metastatic sites requires numerous, timeconsuming and costly tests that does not have very high specificity.

In a further aspect, the invention relates to a method for evaluatingthe prognosis of a cancer the method comprising detecting thephosphorylation status of a Scribble protein, a fragment or variantthereof, wherein the phosphorylation status is indicative of prognosis.In other words, the phosphorylation status is indicative or a good orpoor prognosis. Following evaluating the prognosis, a proper course oftreatment for a patient/subject having cancer may be determined. Forexample, a determination of the likelihood for cancer recurrence,spread, or patient survival, can assist in determining whether a moreconservative or more radical approach to therapy should be taken, orwhether treatment modalities should be combined. For example, whencancer recurrence is likely, it can be advantageous to precede or followsurgical treatment with chemotherapy, radiation, immunotherapy,biological modifier therapy, gene therapy, vaccines, and the like, oradjust the span of time during which the patient is treated.

The term ‘prognosis’ refers to predictions about the likely course ofdisease or disease progression, particularly with respect to likelihoodof disease remission, disease relapse, tumor recurrence, metastasis, anddeath. “Good prognosis” refers to the likelihood that a patientafflicted with cancer, particularly breast cancer, will remaindisease-free (i.e., cancer-free). “Poor prognosis” is intended to meanthe likelihood of a relapse or recurrence of the underlying cancer ortumor, metastasis, or death. Cancer patients classified as having a“good outcome” remain free of the underlying cancer or tumor. Incontrast, “bad outcome” cancer patients experience disease relapse,tumor recurrence, metastasis, or death. In particular embodiments, thetime frame for assessing prognosis and outcome is, for example, lessthan one year, one, two, three, four, five, six, seven, eight, nine,ten, fifteen, twenty or more years. As used herein, the relevant timefor assessing prognosis or disease-free survival time begins with thesurgical removal of the tumor or suppression, mitigation, or inhibitionof tumor growth. Thus, for example, in particular embodiments, a “goodprognosis” refers to the likelihood that a cancer, for example breastcancer patient, will remain free of the underlying cancer or tumor for aperiod of at least five, more particularly, a period of at least tenyears. In further aspects of the invention, a “bad prognosis” refers tothe likelihood that a cancer, for example breast cancer patient, willexperience disease relapse, tumor recurrence, metastasis, or deathwithin less than five years, more particularly less than ten years. Timeframes for assessing prognosis and outcome provided above areillustrative and are not intended to be limiting.

In a further aspect, the invention relates to a method of selecting atreatment for the treatment of cancer, the method comprising detectingthe phosphorylation status of a Scribble protein, a fragment or variantthereof and selecting a treatment depending on said phosphorylationstatus. In an alternative aspect, the invention relates to a method ofselecting a subject for the treatment of cancer, the method comprisingdetecting the phosphorylation status of a Scribble protein, a fragmentor variant thereof and selecting a subject depending on saidphosphorylation status.

‘Treatment’ refers to the management of a patient through medical orsurgical means. The treatment improves or alleviates at least onesymptom of a medical condition or disease and is not required to providea cure. The treatment can encompass any known treatment for cancer.Examples include endocrine therapy, a chemotherapy, a targeted therapyor another hormonal therapy. In a specific embodiment, the endocrinetherapy comprises tamoxifen, raloxifene, megestrol, or toremifene. In afurther specific embodiment, the targeted therapy comprises lapitinab,bevacizumab, trastuzumab, cetuximab, or panitumumab. In a furtherspecific embodiment, another hormonal therapy is an aromatase inhibitorsuch as anastrozole, letrozole, or exemestane, or pure anti-estrogenssuch fulvestrant, or surgical or medical means (goserelin, leuprolide).In one specific embodiment the treatment is treatment with anErbB2-targeted drug.

The phosphorylation status of Scribble, or a fragment or variantthereof, can be used to assess how aggressive a particular cancer ortumour is. Such information is very valuable to a clinician,particularly after conducting surgery to remove the primary tumour.Information on how aggressive the cancer or tumour is can be used todetermine whether a secondary treatment (following surgery) is required.Such a secondary treatment may be any of the treatments listed above, inparticular chemotherapy or radiotherapy. Therefore, in one embodiment,detecting the phosphorylation status of Scribble or a fragment orvariant thereof can be used to decide whether chemotherapy is givenfollowing surgery.

The invention also relates to methods for assessing the aggressivenessof a tumor comprising assessing the phosphorylation status of theScribble protein, a fragment or variant thereof. The term “aggressive”or “invasive” with respect to cancer refers to the proclivity of a tumorfor expanding beyond its boundaries into adjacent tissue. Invasivecancer can be contrasted with organ-confined cancer wherein the tumor isconfined to a particular organ. The invasive property of a tumor isoften accompanied by the elaboration of proteolytic enzymes, such ascollagenases, that degrade matrix material and basement membranematerial to enable the tumor to expand beyond the confines of thecapsule, and beyond confines of the particular tissue in which thattumor is located.

The invention also relates to a method for monitoring the effectivenessof a treatment, wherein the method comprises detecting thephosphorylation status of a Scribble protein, a fragment or variantthereof, and determining the effectiveness of a treatment. Thephosphorylation status of Scribble can be monitored over the course of atreatment period. As the phosphorylation status provides an indicationof the metastatic state or aggressiveness of cancer or tumour,monitoring Scribble phosphorylation over the course of a treatment canindicate how effective the treatment is. In one embodiment the treatmentis an anti-metastatic treatment. In this method, the test sample is froma patient who has received or is receiving treatment.

In one embodiment, a method for monitoring the effectiveness of atreatment comprises the steps of (i) optionally obtaining apre-treatment sample from a patient prior to administration of thetreatment; (ii) optionally detecting or measuring the phosphorylationstatus of Scribble in the pre-treatment sample; (iii) obtaining one ormore post-treatment samples from the subject at selected time intervals;(iv) detecting the phosphorylation status of Scribble in thepost-treatment samples; (v) comparing the phosphorylation status ofScribble in the pre-treatment sample with the phosphorylation in thepost-treatment sample or samples and between different time intervals;and (vi) optionally altering the administration of the treatment to thesubject accordingly. For example, no change or a decrease in thephosphorylation status of Scribble during the course of treatment mayindicate ineffective dosage and the desirability of increasing thedosage. Conversely, an increase in the phosphorylation status ofScribble may indicate efficacious treatment and thus there is no need tochange dosage.

In all the methods described above, a key step is detecting thephosphorylation status of the Scribble protein, or a fragment of variantthereof. In one embodiment detecting or measuring the phosphorylationstatus means detecting whether the protein is phosphorylated or notphosphorylated. In other embodiments it can mean detecting whether, whenconsidering all potential phosphorylation sites (i.e. a phosphorylationsite is a serine or threonine residue) more sites are phosphorylated ormore sites are unphosphorylated. A ratio of phosphorylated tounphosphorylated sites can thus be established and this can beindicative of diagnosis, prognosis or treatment. In an alternativeembodiment, detecting the phosphorylation status may comprise detectingwhether specific residues (i.e. amino acids) within the protein arephosphorylated or not phosphorylated.

In a preferred embodiment, the method comprises detecting thephosphorylation status of at least one of the following residues S1306,S1309, S1348 and S1448 or any combination thereof.

In alternative embodiment, the method comprises detecting thephosphorylation of S1306, S1309, S1348 and S1448.

In a further alternative embodiment, the method comprises detecting thephosphorylation of one of the following:

-   -   a. S1306, S1309 and S1348;    -   b. S1306 and S1309;    -   c. S1348;    -   d. S1348 and S1309;    -   e. S1348 and S1306;    -   f. S1448 and S1309;    -   g. S1448 and S1306;    -   h. S1348 and S1448; or    -   i. S1306, S1348 and S1448    -   j. S1309, S1348 and S1448; or    -   k. S1306, S1309 an S1448.

In a preferred embodiment, the method comprises detecting thephosphorylation of one of a, b or c above.

In an alternative embodiment, the method does not comprise detecting thephosphorylation of S1448.

In a further embodiment, the methods may comprise detecting thephosphorylation status at least one of the following residues S1295.S1298, S1300, T1329, S1330, T1342, S1353, S1445 or combination thereof.The phosphorylation status of any one of these residues or combinationthereof may be detected alone or in combination with any of the abovedescribed residues or combination of residues.

In a further embodiment to the above, the methods comprise detecting thephosphorylation of only one, more or all the above-described sites. Inother words, no other sites are analysed.

Detection of the phosphorylation status of the protein, preferably atone or more of the above-described residues is used in any of thedescribed methods.

Hypophosphorylation of Scribble is indicative of a presence or increasedaggressiveness of cancer. For example

-   -   i. diagnosis of cancer;    -   ii. detecting metastasis of a cancer;    -   iii. evaluating the prognosis of a cancer;    -   iv. selecting a treatment for the treatment of cancer;    -   v. selecting a subject for treatment;    -   vi. monitoring the effectiveness of a treatment and/or    -   vii. assessing the aggressiveness of a tumor.        any one of the following outcomes:    -   i. a positive diagnosis for cancer;    -   ii. an indication that a cancer or tumour has metastasised;    -   iii. a poor prognosis for cancer;    -   iv. a cancer treatment is selected;    -   v. a subject for treatment selected;    -   vi. a treatment is found not to be effective and/or    -   vii. aggressiveness of a tumor is found to be increased        is reached if the protein is unphosphorylated. In an alternative        embodiment, any one of the above outcomes is reached if the        number of dephosphorylated sites is greater than the number of        phosphorylated sites. In preferred embodiments, any one of the        above outcomes is reached if at least one of the following sites        are dephosphorylated S1306, S1309, S1348 and S1448, or any        combination thereof.

In a further preferred embodiment, any one of the above outcomes isreached if the following residues are dephosphorylated: S1306, S1309,S1348 and S1448. In an alternative embodiment, the following residuesare dephosphorylated S1306, S1309 and S1348. In an alternativeembodiment, the residues listed in any of the combinations a to k aboveare dephosphorylated. Preferably, the following residues S1306 and S1309are dephosphorylated. In a further alternative embodiment the followingresidue is dephosphorylated S1348.

In a further embodiment, any one of the above outcomes is reached if thefollowing residues are dephosphorylated: S1295. S1298, S1300, T1329,S1330, T1342, S1353, S1445 or combination thereof (including acombination with the above described residues: S1306, S1309, S1348 andS1448).

In a further embodiment no other residues in the protein, or fragment orvariant thereof are phosphorylated.

In a further embodiment of the methods described herein, the methodsfurther comprise obtaining a test sample from the patient.

The term ‘sample’ or ‘test sample’ as used herein refers preferably toany cell based sample. In a preferred embodiment the sample is tissue,lymph nodes or whole blood. Preferably, the test sample is a tumorsample. Preferably, the sample is a tumor tissue sample. The methodsdescribed herein also include providing multiple samples from a subject.Samples can be taken, days, weeks, or months apart from one another.

Tissue or cell samples can be removed from almost any part of the body.The most appropriate method for obtaining a sample depends on the typeof cancer that is suspected or diagnosed. Biopsy methods include needle,endoscopic, and excisional. In one embodiment the sample may be a tissuesample comprising cancer cells, where the tissue can be fixed,paraffin-embedded or fresh or frozen. In a further embodiment the tissuesample is obtained by fine needle, core or other type of biopsy.

In a further embodiment of the methods described herein, thephosphorylation status of Scribble, a fragment or variant thereof in thesubject's test sample is assessed and compared with the phosphorylationstatus of Scribble, a fragment or variant thereof in a control sample.Thus, in the methods of diagnosis or prognosis described herein, themethod comprises

-   -   a) obtaining a biological test sample from a test subject    -   b) measuring or determining the phosphorylation status of        Scribble, a fragment or variant thereof in the test sample    -   c) comparing the observed phosphorylation status of Scribble to        a predetermined test value wherein said predetermined test is        based on the phosphorylation status of Scribble in a control        sample, for example a sample obtained from an individual patient        or population of individuals that are believed not to have        cancer and wherein a change in the phosphorylation status of        Scribble indicates the presence or increased aggressiveness of        cancer. In particular, as explained below, a reduction in the        phosphorylation status of Scribble indicates the presence or        increased aggressiveness of cancer.

As used herein, a lower level of phosphorylation in the test sample ascompared to the level in the control sample refers to an amount orstatus of phosphorylation of Scribble that is lower than an amount ofphosphorylation of Scribble present in a control sample.

The control sample is taken from a reference cohort, that is one or moresubject of the same species (e.g., human subjects). The reference cohortare preferably healthy subjects. The individual members of a referencecohort may also share other similarities, such as similarities in stageof disease, previous treatment regimens, lifestyle (e.g., smokers ornonsmokers, overweight or underweight), or other demographics (e.g.,age, genetic disposition).

The phosphorylation status of Scribble can be measured and compared witha predetermined reference value. The ‘predetermined reference value’ or‘threshold concentration’ (these terms are used interchangeably herein)can be established by skilled healthcare practitioners. For instance,the predetermined reference value can be established by measuring thelevels of the biomarker in a normal population sample and correlatingsuch levels with factors such as the incidence, severity, and/orfrequency of developing ovarian cancer, more specifically, epithelialovarian cancer. Thus, a subject's phosphorylation status of Scribble ascompared against the phosphorylation status of Scribble in a normalpopulation can be indicative of whether the subject has ovarian cancer.Further, the predetermined reference value is preferably established byusing the same assay technique as is used for measurement of thesubject's biomarker level, to avoid any error in standardization.

In a further aspect of the methods described herein, detecting thephosphorylation of Scribble, or a fragment or variant thereof, comprisescontacting the sample with at least one binding agent, such as anantibody, that is capable of specifically binding at least onephosphorylated or unphosphorylated residue of Scribble. Preferably, theantibody is capable of specifically binding at least one phosphorylatedor unphosphorylated residue selected from S1306, S1309, S1348 and S1448or a combination thereof. Preferably, the antibody is aphospho-antibody.

In the embodiments of this invention where one uses antibodies againstScribble for diagnostic purposes, one can select any immunogenicfragment of Scribble peptides to raise an antibody as is well known toone skilled in the art. The fragments that are immunogenic will lead togeneration of antibodies. Scribble fragments can be readily screened forimmunogenic activity. Preferably, one uses monoclonal antibodies, butone can also use polyclonal antibodies. One can perform animmunohistochemical analysis using a polyclonal or monoclonal antibodyraised against the entire Scribble peptide, or any fragments thereof.

In a further embodiment, the method further comprises determiningwhether the antibody has bound to the protein—i.e. whether anantibody-antigen complex has formed. In one embodiment, the formation ofan antibody-antigen complex is measured using an ELISA. Alternativelybound antibody can be detected using any method known in the art.Examples include 2D gels and ID SDS-PAGE followed by western blotting,dot-blots, and flow cytometry. In an alternative embodiment, boundantibody is detected by in situ analysis of the sample usingimmunohistochemical staining.

Accordingly, the methods further comprise detection or quantitation ofthe antigen-antibody complex. Such methods would be well known to theskilled person. For example, any chemical that detects antigen-antibodybinding may be used in the practice of the invention. In someembodiments, the detection chemicals comprise a labelled polymerconjugated to a secondary antibody. For example, a secondary antibodythat is conjugated to an enzyme that catalyses the deposition of achromogen at the antigen-antibody binding site may be provided. Suchenzymes and techniques for using them in the detection of antibodybinding are well known in the art. In one embodiment the secondaryantibody that is conjugated to an HRP-labelled polymer. Alternatively,the antigen-antibody complex can be detected using any commercialantibody binding detection system. Examples include BIO-PLEX by Bio-Radand fluorescent labels.

Embodiments of the methods of the invention involve (a) contacting atest sample from a subject with a binding agent specific for Scribblephosphorylation, e.g. an antibody as described herein, which is directlyor indirectly labeled with an enzyme; (b) adding a substrate for theenzyme wherein the substrate is selected so that the substrate, or areaction product of the enzyme and substrate, forms fluorescentcomplexes; (c) quantitating Scribble phosphorylation in the sample bymeasuring fluorescence of the fluorescent complexes; and (d) comparingthe quantitated levels to that of a standard.

A another embodiment of the invention comprises the following steps:

-   -   (a) incubating a test sample with a first antibody specific for        Scribble phosphorylation which is directly or indirectly labeled        with a detectable substance, and a second antibody specific for        Scribble phosphorylation which is immobilized;    -   (b) separating the first antibody from the second antibody to        provide a first antibody phase and a second antibody phase;    -   (c) detecting the detectable substance in the first or second        antibody phase thereby quantitating Scribble phosphorylation in        the biological sample; and    -   (d) comparing the quantitated Scribble phosphorylation with a        control.

In a further aspect, the invention provides an antibody capable ofselectively binding to at least one phosphorylated residue or at leastone dephosphorylated residue in a Scribble protein, or fragment orvariant thereof, wherein said residue is selected from S1306, S1309,S1348 and S1448 or a combination thereof.

The term ‘antibody’ as used herein refers to any immunolglobulin,preferably a full-length immunoglobulin. Preferably, the term coversmonoclonal antibodies, polyclonal antibodies, multispecific antibodies,such as bispecific antibodies, intracellular antibodies (or intrabodies)and antibody fragments thereof, so long as they exhibit the desiredbiological activity. Antibodies may be derived from any species, butpreferably are of rodent, for examples rat or mouse, human or rabbitorigin. Alternatively, the antibodies, preferably monoclonal antibodies,may be humanised, chimeric or antibody fragments thereof. The term‘chimeric antibodies’ may also include “primatised” antibodiescomprising variable domain antigen-binding sequences derived from anon-human primate (e.g., Old World Monkey, Ape etc) and human constantregion sequences. The immunoglobulins can also be of any type (e.g. IgG,IgE, IgM, IgD, and IgA), class (e.g., IgGI, IgG2, IgG3, IgG4, IgAI andIgA2) or subclass of immunoglobulin molecule.

The term ‘monoclonal antibody’ refers to a substantially homogenouspopulation of antibody molecules (i.e. the individual antibodiescomprising the population are identical except for possible naturallyoccurring mutations that may be present in minor amounts), produced by asingle clone of B lineage cells, often a hybridoma. Importantly, eachmonoclonal has the same antigenic specificity—i.e. it is directedagainst a single determinant on the antigen.

The production of monoclonal antibodies can be carried out by methodsknown in the art. However, as an example, the monoclonal antibodies canbe made by the hybridoma method (Kohler et al (1975) Nature 256:495),the human B cell hybridoma technique (Kozbor et al., 1983, ImmunologyToday 4: 72), or the EBV-hybridoma technique (Cole et al., 1985,Monoclonal Antibodies and Cancer Therapy, Alan R. Liss, Inc., pp.77-96). Alternatively, the monoclonal antibody can be produced usingrecombinant DNA methods (see, U.S. Pat. No. 4,816,567) or isolated fromphage antibody libraries using the techniques described in Clackson etal (1991) Nature, 352:624-628; Marks et al (1991) J. Mol. Biol.,222:581-597.

Polyclonal antibodies are antibodies directed against differentdeterminants (epitopes). This heterogenous population of antibody can bederived from the sera of immunised animals using various procedures wellknown in the art.

The term ‘bispecific antibody’ refers to an artificial antibody composedof two different monoclonal antibodies. They can be designed to bindeither to two adjacent epitopes on a single antigen, thereby increasingboth avidity and specificity, or bind two different antigens fornumerous applications, but particularly for recruitment of cytotoxic T-and natural killer (NK) cells or retargeting of toxins, radionuclides orcytotoxic drugs for cancer treatment (Holliger & Hudson, NatureBiotechnology, 2005, 9, 23). The bispecific antibody may have a hybridimmunoglobulin heavy chain with a first binding specificity in one arm,and a hybrid immunoglobulin heavy chain-light chain pair (providing asecond binding specificity) in the other arm. This asymmetric structurefacilitates the separation of the desired bispecific compound fromunwanted immunoglobulin chain combinations, as the presence of animmunoglobulin light chain in only one half of the bispecific moleculeprovides for a facile way of separation (WO 94/04690; Suresh et al.,Methods in Enzymology, 1986, 121:210; Rodrigues et al., 1993, J. ofImmunology 151:6954-6961; Carter et al., 1992, Bio/Technology10:163-167; Carter et al., 1995, J. of Hematotherapy 4:463-470; Merchantet al., 1998, Nature Biotechnology 16:677-681.

Methods to prepare hybrid or bispecific antibodies are known in the art.In one method, bispecific antibodies can be produced by fusion of twohybridomas into a single ‘quadroma’ by chemical cross-linking or geneticfusion of two different Fab or scFv modules (Holliger & Hudson, NatureBiotechnology, 2005, 9, 23).

The term ‘chimeric’ antibody refers to an antibody in which differentportions are derived from different animal species. For example, achimeric antibody may derive the variable region from a mouse and theconstant region from a human. In contrast, a ‘humanised antibody’ comespredominantly from a human, even though it contains non-human portions.Specifically, humaised antibodies are human immunoglobulins (recipientantibody) in which residues from a hypervariable region of the recipientare replaced by residues from hypervariable regions of a non-humanspecies (donor antibody) such as mouse, rat, rabbit or nonhuman primatehaving the desired specificity, affinity and capacity. In someinstances, framework region (FR) residues of the human immunoglobulinare replaced by corresponding non-human residues. Furthermore, humanisedantibodies may comprise residues that are not found in the recipientantibody or in the donor antibody. These modifications are made tofurther refine antibody performance. In general, the humanised antibodywill comprise substantially all of at least one, and typically two,variable domains, in which all or substantially all of the hypervariableloops correspond to those of a non-human immunoglobulin and all orsubstantially all of the FRs are those of a human immunoglobulinsequence. The humanised antibody optionally also will comprise at leasta portion of an immunoglobulin constant region (Fc), typically that of ahuman immunoglobulin.

Recombinant antibodies such as chimeric and humanised monoclonalantibodies can be produced by recombinant DNA techniques known in theart. Completely human antibodies can be produced using transgenic micethat are incapable of expressing endogenous immunoglobulin heavy andlight chains genes, but which can express human heavy and light chaingenes. The transgenic mice are immunized in the normal fashion with aselected antigen. Monoclonal antibodies directed against the antigen canbe obtained using conventional hybridoma technology. The humanimmunoglobulin transgenes harboured by the transgenic mice rearrangeduring B cell differentiation, and subsequently undergo class switchingand somatic mutation. Thus, using such a technique, it is possible toproduce therapeutically useful IgG, IgA, IgM and IgE antibodies. For anoverview of this technology for producing human antibodies, see Lonbergand Huszar (1995, Int. Rev. Immunol. 13:65-93). For a detaileddiscussion of this technology for producing human antibodies and humanmonoclonal antibodies and protocols for producing such antibodies, see,for example, U.S. Pat. Nos. 5,625,126; 5,633,425; 5,569,825; 5,661,016;5,545,806; each of which is incorporated herein by reference in itsentirety. Other human antibodies can be obtained commercially from, forexample, Abgenix, Inc. (Freemont, Calif.) and Genpharm (San Jose,Calif.).

The term ‘antigen-binding fragment’ in the context of the presentinvention refers to a portion of a full length antibody where suchantigen-binding fragments of antibodies retain the antigen-bindingfunction of a corresponding full-length antibody. The antigen-bindingfragment may comprise a portion of a variable region of an antibody,said portion comprising at least one, two, preferably three CDRsselected from CDR1, CDR2 and CDR3. The antigen-binding fragment may alsocomprise a portion of an immunoglobulin light and heavy chain. Examplesof antibody fragments include Fab, Fab′, F(ab′)2, scFv, di-scFv, andBiTE (Bi-specific T-cell engagers), Fv fragments including nanobodies,diabodies, diabody-Fc fusions, triabodies and, tetrabodies; minibodies;linear antibodies; fragments produced by a Fab expression library,anti-idiotypic (anti-Id) antibodies, CDR (complementary determiningregion), and epitope-binding fragments of any of the above thatimmunospecifically bind to a target antigen such as a cancer cellantigens, viral antigens or microbial antigens, single-chain orsingle-domain antibody molecules including heavy chain only antibodies,for example, camelid VHH domains and shark V-NAR; and multispecificantibodies formed from antibody fragments. For comparison, a full lengthantibody, termed ‘antibody’ is one comprising a VL and VH domains, aswell as complete light and heavy chain constant domains.

The antibody may also have one or more effector functions, which referto the biological activities attributable to the Fc region (a nativesequence Fc region or amino acid sequence variant Fc region engineeredaccording to methods in the art to alter receptor binding) of anantibody. Examples of antibody effector functions include Clq binding;complement dependent cytotoxicity; Fc receptor binding;antibody-dependent cell-mediated cytotoxicity (ADCC); phagocytosis; downregulation of cell surface receptors (e.g., B cell receptor; BCR), etc.

The antibody can also be a functionally active fragment, derivative oranalog of an antibody that immunospecifically binds to a target antigensuch as a cancer cell antigen, viral antigen, or microbial antigen orother antibodies bound to tumour cells. In this regard, functionallyactive means that the fragment, derivative or analog is able to elicitanti-idiotype antibodies that recognise the same antigen that theantibody from which the fragment, derivative or analog is derivedrecognised. Specifically, in an exemplary embodiment the antigenicity ofthe idiotype of the immunoglobulin molecule can be enhanced by deletionof framework and CDR sequences that are C-terminal to the CDR sequencethat specifically recognizes the antigen. To determine which CDRsequences bind the antigen, synthetic peptides containing the CDRsequences can be used in binding assays with the antigen by any bindingassay method known in the art (e.g., the BIA core assay), see, forexample, Kabat et al., 1991, Sequences of Proteins of ImmunologicalInterest, Fifth Edition, National Institute of Health, Bethesda, Md.;Kabat E et al., 1980, J. of Immunology 125(3):961-969).

The term ‘antibody’ may also include a fusion protein of an antibody, ora functionally active fragment thereof, for example in which theantibody is fused via a covalent bond (e.g., a peptide bond), at eitherthe N-terminus or the C-terminus to an amino acid sequence of anotherprotein (or portion thereof, such as at least 10, 20 or 50 amino acidportion of the protein) that is not the antibody. The antibody orfragment thereof may be covalently linked to the other protein at theN-terminus of the constant domain.

Furthermore, the antibody or antigen-binding fragments of the presentinvention may include analogs and derivatives of antibodies orantigen-binding fragments thereof that are either modified, such as bythe covalent attachment of any type of molecule as long as such covalentattachment permits the antibody to retain its antigen bindingimmunospecificity. Examples of modifications include glycosylation,acetylation, pegylation, phosphorylation, amidation, derivatization byknown protecting/blocking groups, proteolytic cleavage, linkage to acellular antibody unit or other protein, etc. Any of numerous chemicalmodifications can be carried out by known techniques, including, but notlimited to specific chemical cleavage, acetylation, formylation,metabolic synthesis in the presence of tunicamycin, etc. Additionally,the analog or derivative can contain one or more unnatural amino acids.

The antibodies or antigen-binding fragments of the present invention mayalso have modifications (e.g., substitutions, deletions or additions) inthe Fc domain of the antibody. Specifically, the modifications may be inthe Fc-hinge region and result in an increased binding for the FcRnreceptor (WO 97/34631).

In another embodiment, the phosphorylation status of the scribbleprotein, a fragment or variant thereof is assessed using massspectrometry techniques. Prolonged expression of CD74 has also beendemonstrated to lead to a decrease in expression levels of Scribble.Accordingly, in a further aspect, the methods described herein includemeasuring and detecting a decrease in the expression levels of Scribble.In a further embodiment, the methods described herein may includemeasuring both the phosphorylation status and expression levels ofScribble. In one embodiment dephosphorylation of Scribble or a fragmentor variant thereof, or more preferably, dephosphorylation of one of thespecific residues described herein and a decrease in the expressionlevels is indicative of cancer, metastasis of cancer, a poor prognosisand/or affect whether a patient is selected for treatment or the choiceof treatment for the patient and is indicative of whether a treatment iseffective.

In an alternative embodiment, any of the methods described herein can beused in combination with assessment of conventional clinical factors(e.g. tumour size, tumour grade, lymph node status and family history)and/or analysis of other molecular markers, for example analysis of theexpression level of a second or more molecular marker. Such marker couldbe a biomarker involved in cell cycle regulation, DNA replication,transcription, signal transduction, cell proliferation, invasion ormetastasis. Examples of such markers include EGFR, Her2/neu, Ki67, p53,estrogen and progesterone hormone. In this manner the methods of theinvention permit a more accurate evaluation of cancer prognosis. Thus,one aspect of the invention, a secondary diagnostic step can beperformed. For example, if a level of phosphorylation of Scribble or afragment or variant thereof is found to indicate the presence oraggressiveness of cancer, then an additional method of detecting thecancer can be performed to confirm the presence of the cancer. Any of avariety of additional diagnostic steps can be used, such as mammography(breast cancer), ultrasound, PET scanning, MRI, or any other imagingtechniques, biopsy, clinical examination, ductogram, or any othermethod.

Kits for practicing the methods of the invention are further provided. A‘kit’ refers to any manufacture (e.g., a package or a container)comprising at least one reagent, e.g. a binding agent such as anantibody, for specifically detecting the phosphorylation status ofScribble. The kit may be promoted, distributed, or sold as a unit forperforming the methods of the present invention. Additionally, the kitsmay contain a package insert describing the kit and methods for its use.The kit may also comprise a solid support such as microtiter multi-wellplates.

For example, the kit can contain reagents, tools, and instructions fordetermining an appropriate therapy for a cancer patient. Such a kit caninclude reagents for collecting a tissue sample from a patient, such asby biopsy, and reagents for processing the tissue. The kit can alsoinclude one or more reagents for detecting the phosphorylation status ofScribble. In one embodiment, the kit may also comprise one or morereagents for performing a gene expression analysis, such as reagents forperforming RT-PCR, Northern blot, Western blot analysis, orimmunohistochemistry to determine scribble expression levels in a tumorsample. Appropriate buffers for the assays can also be included.

A kit can contain separate containers, dividers or compartments for thereagents and informational material.

In particular embodiments, kits for practicing the methods of theinvention are provided. Such kits are compatible with both manual andautomated immunohistochemistry techniques (e.g., cell staining). Thesekits comprise at least one antibody capable of specifically detectingthe phosphorylation status of Scribble. Chemicals for the detection ofantibody binding to Scribble, a counterstain, and a bluing agent tofacilitate identification of positive staining cells are optionallyprovided. Alternatively, the immunochemistry kits of the presentinvention are used in conjunction with commercial antibody bindingdetection systems, such as, for example the BIOPLEX assay by Bio-Rad.Any chemicals that detect antigen-antibody binding may be used in thepractice of the invention. In some embodiments, the detection chemicalscomprise a labelled polymer conjugated to a secondary antibody. Forexample, a secondary antibody that is conjugated to an enzyme thatcatalyses the deposition of a chromogen at the antigen-antibody bindingsite may be provided. Such enzymes and techniques for using them in thedetection of antibody binding are well known in the art. In oneembodiment, the kit comprises a secondary antibody that is conjugated toan HRP-labeled polymer. Chromogens compatible with the conjugated enzyme(e.g., DAB in the case of an HRP-labeled secondary antibody) andsolutions, such as hydrogen peroxide, for blocking non-specific stainingmay be further provided. The kits of the present invention may alsocomprise a counterstain, such as, for example, hematoxylin. A bluingagent (e.g., ammonium hydroxide) may be further provided in the kit tofacilitate detection of positive staining cells.

In another embodiment, the immunohistochemistry kits of the inventioncomprise at least two reagents, e.g., antibodies, for specificallydetecting the phosphorylation status of Scribble, or a fragment orvariant thereof. Preferably, each antibody is capable of specificallybinding a different residue on Scribble. Preferably, each antibody iscapable of binding to a different residue selected from S1306, S1309,S1348 and S1448. Each antibody may be provided in the kit as anindividual reagent or, alternatively, as an antibody cocktail comprisingall of the antibodies directed to the different biomarkers of interest.Furthermore, any or all of the kit reagents may be provided withincontainers that protect them from the external environment, such as insealed containers. Positive and/or negative controls may be included inthe kits to validate the activity and correct usage of reagents employedin accordance with the invention. Controls may include samples, such astissue sections, cells fixed on glass slides, etc., known to be eitherpositive or negative for Scribble phosphorylation. The design and use ofcontrols is standard and well within the routine capabilities of thoseof ordinary skill in the art.

In other embodiments, kits for practicing the methods of the inventionare provided, wherein the kit includes at least one antibody for thedetection of Scribble phosphorylation status and one means for detectingexpression levels of Scribble. Such kits comprise, for example, at leastone nucleic acid probe that specifically binds to a Scribble nucleicacid or a fragment or variant thereof. In an alternative embodiment, themeans for detecting expression levels of Scribble can comprise measuringprotein levels of Scribble. Examples include immunohistochemistry orwestern blot or any other proteomics technique.

In another aspect of the invention I describe a method of treatingcancer, wherein the method comprises administering a therapeuticallyeffective amount of an agent capable of phosphorylating or preventingthe dephosphorylation of a Scribble protein, or fragment or variantthereof. Preferably the agent is capable of phosphorylating orpreventing the dephosphorylation of at least one residue in a Scribbleprotein, fragment or variant thereof, wherein said residue is selectedfrom S1306, S1309, S1348 and S1448 or a combination thereof. In oneexample, the agent is kinase. In particular the agent may be an ERK mapkinase. Preferably the kinase is specific to Scribble, or specificallyphosphorylates at least one residue selected from S1306, S1309, S1348and S1448 or a combination thereof. Alternatively, the agent may be aphosphatase. In one example, the phosphatase is PP2A. Again, preferablythe phosphatase is specific to Scribble, or more preferably specific forat least one residue selected from S1306, S1309, S1348 and S1448 or acombination thereof. In order to achieve this specificity the kinase orphosphatase may be genetically modified. In a further alternative, theagent may be a vector capable of expressing a mutated Scribble protein,or fragment or variant thereof, wherein at least one of the followingresidues, S1306, S1309, S1348 and S1448, mimic the constitutivelyphosphorylated state, or are incapable of being dephosphorylated.

By ‘therapeutically effective amount’ of an agent it is meant an amountof active agent that is capable of preventing or at least slowing down(lessening) cancer cell migration or metastases. Dosages andadministration of an agent of the invention in a pharmaceuticalcomposition may be determined by one of ordinary skill in the art ofclinical pharmacology or pharmacokinetics. An effective amount of theantagonist to be employed therapeutically will depend, for example, uponthe therapeutic objectives, the route of administration, and thecondition of the mammal. Accordingly, it will be necessary for thetherapist to titre the dosage and modify the route of administration asrequired to obtain the optimal therapeutic effect. A typical dailydosage might range from about 10 ng/kg to up to 100 mg/kg of themammal's body weight or more per day, preferably about 1 pg/kg/day to 10mg/kg/day. Doses may include an antibody amount anywhere in the range of0.1 to 20 mg/kg of bodyweight or more preferably 1, 5, 10 mg/kg ofbodyweight.

Thus, the present invention also relates to pharmaceutical compositionscomprising a therapeutically effective amount of an agent capable ofphosphorylating or preventing the dephosphorylation of Scribble,preferably at least one of the residues S1306, S1309, S1348 and S1448,and a pharmaceutically acceptable carrier.

Pharmaceutical forms of the invention suitable for injectable use,include sterile aqueous solutions such as sterile phosphate-bufferedsaline (where water soluble) or dispersions and sterile powders for theextemporaneous preparation of sterile injectable solutions and or one ormore carrier. Alternatively, injectable solutions may be deliveredencapsulated in liposomes to assist their transport across cellmembrane. Alternatively or in addition such preparations may containconstituents of self-assembling pore structures to facilitate transportacross the cellular membrane. It must be stable under the conditions ofmanufacture and storage and must be preserved against thecontaminating/destructive action of microorganisms such as, for example,bacteria and fungi.

The carrier can be a solvent or dispersion medium containing, forexample, water, ethanol, polyol (for example, glycerol, propylene glycoland liquid polyethylene glycol, and the like), suitable mixturesthereof, and vegetable oils. The proper fluidity can be maintained, forexample, by the use of a coating such as, for example, lecithin, by themaintenance of the required particle size in the case of dispersion andby the use of surfactants. Preventing the action of microorganisms inthe compositions of the invention is achieved by adding antibacterialand/or antifungal agents, for example, parabens, chlorobutanol, phenol,sorbic acid, thimerosal and the like. In many cases, it will bepreferable to include isotonic agents, for example, sugars or sodiumchloride. Prolonged absorption of the injectable compositions can bebrought about by the use in the compositions of agents delayingabsorption, for example, aluminum monostearate and gelatin.

Sterile injectable solutions are prepared by incorporating the activecompounds in the required amount in the appropriate solvent with severalof the other ingredients enumerated above, as required, followed byfiltered sterilization. Generally, dispersions are prepared byincorporating the various sterilized active ingredient into a sterilevehicle which contains the basic dispersion medium and the requiredother ingredients from those enumerated above. In the case of sterilepowders for the preparation of sterile injectable solutions, thepreferred methods of preparation are vacuum drying and freeze-drying, toyield a powder of the active ingredient plus any additional desiredingredient from previously sterile-filtered solution thereof.

The active ingredient may be held within a matrix which controls therelease of the active agent. Preferably, the matrix comprises asubstance selected from the group consisting of lipid, polyvinylalcohol, polyvinyl acetate, polycaprolactone, poly(glycolic)acid,poly(lactic)acid, polycaprolactone, polylactic acid, po lyan hydrides,polylactide-co-glycolides, polyamino acids, polyethylene oxide, acrylicterminated polyethylene oxide, polyamides, polyethylenes,polyacrylonitriles, polyphosphazenes, poly(ortho esters), sucroseacetate isobutyrate (SAIB), and combinations thereof and other polymers.

Pharmaceutically acceptable carriers and/or diluents may also includeany and all solvents, dispersion media, coatings, antibacterials and/orantifungals, isotonic and absorption delaying agents and the like. Theuse of such media and agents for pharmaceutical active substances iswell known in the art. Except insofar as any conventional media or agentis incompatible with the active ingredient, use thereof in thetherapeutic compositions is contemplated.

In a further aspect of the invention I describe a method of selecting orexcluding a subject for enrolment in a clinical trial or stratifying asubject population for analysis of a clinical trial, the methodcomprising detecting the phosphorylation status of a Scribble protein,or fragment or variable thereof, in a sample from at least one subjectand selecting or excluding a subject or stratifying a subject populationbased on the phosphorylation of Scribble.

A further aspect of the invention relates to a diagnostic device usefulin carrying out the methods of the invention can be constructed in anyform adapted for the intended use. In one embodiment, the device of theinvention comprises a solid support (such as a strip or dipstick), witha surface that functions as a lateral flow matrix defining a flow pathfor a biological sample such as whole blood. The invention also relatesto a immunochromatographic assay for the diagnosis of cancer comprisingone or more immobilized antibody for the detection of thephosphorylation status of Scribble, a fragment or variant thereof.

In a final aspect of the invention I describe a method of visualising ordetermining the intracellular localisation of Scribble in a cell,particularly an apical or basolateral location, the method comprisingadministering an antibody capable of binding at least one phosphorylatedor unphosphorylated residue in Scribble selected from S1306, S1309,S1348 and S1448 or combination thereof, wherein the antibody is furtherconjugated to a reporter. In one embodiment the reporter is luminescentor fluorescent.

While the foregoing disclosure provides a general description of thesubject matter encompassed within the scope of the present invention,including methods, as well as the best mode thereof, of making and usingthis invention, the following examples are provided to further enablethose skilled in the art to practice this invention and to provide acomplete written description thereof. However, those skilled in the artwill appreciate that the specifics of these examples should not be readas limiting on the invention, the scope of which should be apprehendedfrom the claims and equivalents thereof appended to this disclosure.Various further aspects and embodiments of the present invention will beapparent to those skilled in the art in view of the present disclosure.

“and/or” where used herein is to be taken as specific disclosure of eachof the multiple specified features or components with or without theother at each combination unless otherwise dictated. For example “A, Band/or C” is to be taken as specific disclosure of each of (i) A, (ii)B, (iii) C, (iv) A and B, (v) B and C or (vi) A and B and C, just as ifeach is set out individually herein.

Unless context dictates otherwise, the descriptions and definitions ofthe features set out above are not limited to any particular aspect orembodiment of the invention and apply equally to all aspects andembodiments which are described.

The invention is further described in the following non-limitingexamples.

Example I Materials and Methods

Unless indicated otherwise in the text, chemicals and HPLC solvents werepurchased from Thermo Fisher (Loughborough, United Kingdom). The highestavailable grades were used.

Cell Culturing

Breast cancer cell lines MDA-MB-435, MDA-MB-231, MCF7, and ZR-75.1 andhuman embryonic kidney 293T/s (HEK293T/s) were grown on RPMI 40Ultraglutamine medium supplemented with 10% fetal calf serum at 37° C.and 5% CO2 and split every second day. The cells were grown to about 80%confluency, detached, washed with phosphate-buffered saline (PBS), andstored at −80° C. until needed for analysis.

SILAC Labeling

The cell cultures were labeled using the SILAC Labeling Kit from ThermoFisher following the manufacturer's instructions and as described by Onget al. [13]. All cell cultures were labeled for at least five doublingtimes to ensure complete protein labeling.

Transient Transfection

This was performed as previously described using HEK293T and MCF7 cells[5].

Generation of Stably Transfected HEK293s Cells Expressing CD74 under theTetracycline-Inducible Promoter

To generate these cell lines, I used an HEK293s derivative stablytransfected with the TetR construct and expressing the repressor(HEK293s-TetR) [14]. The cells and the TetO plasmid were kind gifts fromDr Phil Reeves from the University of Essex. The CD74 sequence wassubcloned into the TetO plasmid using the following primers:

SEQ ID NO: 2 FOR: 5′-GGAATTCGCCACCATGCACAGGAGGAGAAGCAG-3′: SEQ ID NO: 3REV: 5′-GCGGCCGCTCACATGGGGACTGGGCCCAGATCC-3′:from a construct described previously and using the same cloningstrategy as described by Reeves et al. for rhodopsin [14]. The TetOCD74plasmid was sequenced to validate the sequence and then transfected into the HEK293s-TetR cells. The transfectants were selected onG418-containing medium for about 3 weeks until G418-resistant TetR/TetOcolonies could be isolated. Twelve colonies were isolated initially, andafter screening for inducible CD74 expression, five positive colonieswere expanded and stored as stock for further experiments.

CD74 Overexpression and Knockdown

The TetR/TetO-CD74 HEK293s cells were induced with 1 μg/ml tetracyclinefor various periods of time. An untreated TetR/TetOCD74 control was mocktreated for the same periods of time. An additional control with TetRHEK293s cells treated with tetracycline was also included in most of theexperiments to identify possible tetracycline-induced phenomena that areindependent of CD74. CD74 knockdown in MDA-435-MB cells was performedusing siRNA from Santa Cruz Biotechnology (Santa Cruz, Calif.) accordingto the manufacturer's instruction.

Tumor Tissue Acquisition

All tissues were collected under Local Research Ethics Committee (LREC)and National Health Services (NHS) Trust approval as previouslydescribed [5, 15]. Tumor tissue was placed on ice immediately in theoperating theater. The tissue was assessed and cut by the pathologist onice before being divided up with a proportion of the tissue snap frozenin liquid nitrogen and the remainder fixed in formalin with the shortestpossible delay.

Membrane Protein Isolation

Approximately 20 to 50 mg of frozen tissue from a surgery specimen orcore biopsy was snap frozen in liquid nitrogen and pulverized in aBioPulverizer stainless steel device (BioSpec Products, Bartlesville,Okla.). The homogenized sample was placed on ice and mixed with 500 μlof permeabilization solution containing PBS, 0.2% saponin, and proteaseand phosphatase inhibitors (Roche Diagnostics, Burgess Hill, UnitedKingdom). For cultured cells, the homogenization step was omitted andthe cells were directly permeabilized. The samples were incubated on icewith intermittent mixing for 15 minutes and centrifuged at 14,000 rpm ina refrigerated centrifuge for 45 minutes. Following centrifugation, thesupernatant containing the water-soluble proteins was removed and storedfrozen until needed. The pellet was washed with 500 μl of PBS containingprotease and phosphatase inhibitors and centrifuged as above. The washedpermeabilized pellet was extracted with 100 μl of membrane proteinextraction buffer containing 1% (vol/vol) IGEPAL in 50 mM Tris-HCl (pH7.4), 150 mM NaCl, and protease and phosphatase inhibitors as above,resuspended, and incubated on ice for 10 to 15 minutes. Cultured cellswere extracted in 1 ml of buffer per 107 cells. The sample was thencentrifuged at 4° C. and 14,000 rpm for 15 minutes. The supernatantcontaining the membrane proteins was recovered and either processedimmediately as described below or stored at −80° C. until needed.

Immunoprecipitation

Membrane protein fractions extracted as above containing about 0.5 mg oftotal protein (estimated by dye-binding assay) were diluted 1:1 withbinding buffer containing 50 mM Tris-HCl (pH 7.4) and 150 mM NaCl andincubated with 6 μg of LN2 antibody for 30 minutes at room temperatureto allow antibody binding to the CD74 extracellular domain. To eachtube, 60 μl of protein A/G agarose (Santa Cruz Biotechnology) prewashedwith 1 ml of binding buffer was then added. The tubes were furtherincubated for 1 hour at room temperature on a rotator. I found thatbecause of the inclusion of protease and phosphatase inhibitors in themembrane extraction buffer, performing the experiments at roomtemperature gave better yields and throughput. The agarose beads werewashed three times with binding buffers and the precipitated proteinseluted with 30 μl of sodium dodecyl sulfate sample buffer containing 12mM DTT for 5 minutes at 100° C. The samples were then cooled on ice andalkylated with 60 mM iodoacetamide for 30 minutes in the dark. ForWestern blot analysis, an aliquot of the sample was separated bydenaturing polyacrylamide gel electrophoresis (PAGE) and transferredonto a polyvinylidene fluoride (PVDF) membrane. Forimmunoprecipitation/mass spectrometry (IP/MS) analysis, the sample wasseparated and the gel sliced into five size-resolved fractions, digestedwith trypsin, and analysed by liquid chromatography/tandem massspectrometry (LC-MS/MS).

Protein Digestion and Preparation of Samples for Mass Spectrometry

The protein samples were mixed with 2× sodium dodecyl sulphate samplebuffer, reduced, alkylated, and subjected to in-gel digestion aspreviously described [15]. The SILAC-labeled proteins were separatedinto up to 10 fractions by a semipreparative PAGE before digestion.

Isolation of Phosphopeptides

Aliquots containing about 0.5 mg of total protein were separated by asemipreparative PAGE on single-well minigel. Up to 10 size-resolvedfractions were excised and digested as described above. The trypticpeptides were extracted from the gel pieces, and 10% of the extractedpeptides were removed for quantitative analysis of protein abundance anddried in a vacuum concentrator. The remaining 90% were also dried anddissolved in 100 μl of 80% acetonitrile containing 2% formic acid andused to isolate phosphorylated peptides. Phosphopeptides were isolatedusing the Magnetic TiO2 Phosphopeptide Isolation Kit from Thermo Fisherfollowing the manufacturer's instructions.

Nanoscale LC-MS/MS Analysis

Protein digest analysis by electrospray ionization MS was performed on ahybrid LTQ/Orbitrap Velos instrument (Thermo Fisher) interfaced to asplitless nanoscale HPLC (Ultimate 3000; Dionex, Loughborough, UnitedKingdom). The peptides were desalted and concentrated online at a flowof 1 μl/min on a 2-cm-long, 0.1-mm i.d. trap column packed with 5-μm C18particles (Dionex). Following concentration/desalting, the peptides wereeluted from the trap column and separated in a 90-minute gradient of 2%to 30% (vol/vol) acetonitrile in 0.1% (vol/vol) formic acid at a flowrate of 0.3 μl/min. The separation column was a 15-cm-long, 0.1-mm i.d.pulled tip packed with 5-μm C18 particles (Nikkyo Technos Co, Tokyo,Japan). The eluting peptides were electrosprayed directly from thepacked tip into the LTQ/Orbitrap Velos mass spectrometer by applying1.75 kV through a liquid junction interface. The LTQ/Orbitrap Velos wasoperated in the Top 20 data-dependent mode where it first executes twohigh-resolution scans at a resolution of 30,000 (at 400 m/z) followed by20 MS/MS scans for the 20 most abundant peptide ions having a chargestate>1. During the high-resolution scans, the Orbitrap analyzer was setto accumulate 106 ions for the maximum of 0.5 second. During MS/MSscans, the LTQ was set to accumulate 5000 precursor ions for the maximumof 0.1 second. The normalized collision energy was set to 30; minimumsignal intensity required was set to 500, activation time to 10milliseconds, and activation Q to 0.250. A dynamic exclusion procedurewas implemented to avoid repetitive analysis of abundant peptide ions:After a peptide ion has been analysed once, its m/z was put in theexclusion list for 30 seconds. The mass calibration was internal bymeans of lock mass. The ambient ion of 445.12 m/z was used for thispurpose throughout all experiments. For targeted detection of Scribblepeptides, a mixed mode analysis was used in which a full scan wasperformed as described above; the next four selected reaction monitoring(SRM) scans were performed to isolate and fragment two Scribble reporterpeptides, VSLVGADDLR (SEQ ID NO: 4) and VQSPEPPAPER (SEQ ID NO:5), intheir heavy and light SILAC isoforms. Finally, seven data-dependentMS/MS scans were performed to isolate and fragment the seven mostabundant peptide ions detected in the high-resolution full scan.

Data Analysis

MS/MS data were analyzed by MaxQuant and the Andromeda search engine asdescribed in [16-18]. The MaxQuant searches were performed using areverse database to calculate false discovery rate (FDR). Results fromthe Andromeda engine were filtered at both peptide and protein level. Inboth cases, the cutoff was at 1% FDR. For SILAC ratios of unmodifiedpeptides and phosphopeptides, the quantitative analysis was performed byMaxQuant and further evaluated by statistical tests using MicrosoftExcel.

Western Blot Analysis and Immunohistochemical Analysis of Tumor Tissue

Immunoblot analysis and immunohistochemistry were performed aspreviously described [15]. For CD74 detection in immunohistochemical(IHC) and for immunoprecipitation, the mouse monoclonal antibody LN2from Santa Cruz Biotechnology was used. δ-Tubulin and Scribbleantibodies were also from Santa Cruz Biotechnology. IHC staining wasscored using the immunoreactivity score (IRS) scores as implemented forHer2 staining, taking into account staining intensity and the percentageof positive cells: intensity ranges from 1 to 3 for weak, moderate, andstrong staining, respectively. Percentage ranges from 1 to 5 for <10%,10% to 25%, 25% to 50%, 50% to 75%, and >75% staining of the malignantcells; total score=intensity+percentage.

Indirect Immunofluorescence and Colocalization Analysis

Cells to be analyzed were grown in eight-well chamber slides (Lab-Tek;Fisher Scientific, Loughborough, United Kingdom), treated and fixed in4% buffered paraformaldehyde, and permeabilized in PBS containing 0.5%Triton X-100 for 5 minutes. The cells were blocked in 5% BSA in PBS for1 hour and stained with mouse anti-Scribble antibody and rabbitanti-CD74 antibody (1:100 dilution) diluted in PBS containing 1% BSA for1 hour at room temperature (RT). The cells were washed three times inPBS containing 0.1% (vol/vol) Tween 20. The cells were then incubatedwith secondary antibody solution containing goat anti-mouse Cy5 (Abcam,Cambridge, United Kingdom) and goat anti-rabbit fluoresceinisothiocyanate (Abcam), diluted 1:1000 in PBS containing 1% BSA and 0.1%Tween 20 for 45 minutes. The cells were then washed three times in PBScontaining 0.1% Tween 20 and analyzed by laser scanning confocalmicroscopy on a Nikon Eclipse Ti microscope. Colocalized pixels wereidentified using the ImageJ plugin ColocalizeRGB.

Fluorescence-Activated Cell Sorting (FACS) Analysis

The cells were stained as above and counted in a BD FACS Ariainstrument. A secondary antibody-only control was included to estimatenonspecific staining.

Results

In a previous study, I found that CD74 is more abundant in lymphnode-metastatic triple-negative tumors compared to nonmetastatictriple-negative breast cancer (TNBC) tumors. This conclusion was basedon data obtained by mass spectrometry and pooled tumor protein lysatesfrom six metastatic and six nonmetastatic triple-negative breast tumors[5]. Since this analysis did not discriminate between expression in themalignant cells and other cells in the tumor, I decided to reexamineCD74 expression in another collection of triple-negative breast tumors,this time using immunohistochemical staining instead of massspectrometry. The results, shown in FIG. 6 confirmed the previouslyreported observation that CD74 tends to be more abundant in lymphnode-metastatic triple-negative breast tumors. I stained 9 nodepositivetumors and 10 node-negative tumors. Seven of the nodepositive tumorsshowed strong CD74 staining in the malignant cells, while only 3 of the10 node-negative tumors showed such staining. This corresponds to a Pvalue of 0.0409 by the nonparametric Mann-Whitney t test, indicatingthat aberrant CD74 expression in the malignant cells is associated withincreased metastasis. A similar pattern was observed when variousestablished breast cancer cell lines were studied for CD74 expression:The most metastatic line, MDA-435-MD, was the only one to showconstitutive CD74 expression. All other tested cell lines did notexpress the protein normally at detectable level, although some of themcould be induced to express small amounts if treated with interferon γ([4,5]). To investigate whether CD74 expression contributes to invasionof MDA-435-MB cells, I used siRNA to knock down CD74 and performed woundhealing assays. The wound healing assay is a standard assay in the artto measure the ability of cells to migrate and invade, both of which area very important part of metastasis. Indeed, when the expression of CD74was downregulated by siRNA, the wound healing ability of MDA-435-MBcells was diminished (FIG. 7). Thus, tumour specimen analysis and invitro experiments with cultured cells provided additional evidences forthe involvement of CD74 in the invasion and metastasis of breast cancer.To identify likely targets of CD74 in this context, I decided to followa quantitative approach based on stable isotope labelling, in whichtotal protein abundance and protein phosphorylation were quantifiedsimultaneously in cells engineered to express the protein in a highlyregulated way. This allowed the identification of phosphorylationhotspots: protein phosphorylation sites that are significantly affectedby CD74 overexpression while the corresponding total protein abundancesare not. This combined genome-scale proteomic screen pinpointed thetumor suppressor protein Scribble as a likely target of CD74 in breastcancer. While the total amount of Scribble, as measured by quantitativehigh-resolution mass spectrometry, did not change dramatically after 24hours of CD74 expression, three specific phosphopeptides decreasedsignificantly in the cells overexpressing CD74. FIGS. 1 and 8 illustratethe results obtained using HEK293s cells expressing CD74 under thecontrol of a tetracycline-inducible promoter. Similar results wereobtained in transiently transfected MCF7 cells. Three of thephosphorylation sites on two of the phosphopeptides conform well to thecanonical mitogen-activated protein kinase (MAPK) phosphorylationconsensus, P-X-S/T-P, and have been detected previously in large-scalephosphoproteomics studies [19, 20]. The third peptide is alsophosphorylated on a proline-directed site and could be either MAPK orcyclin-directed kinase target. Following the identification of Scribbleas likely target of CD74, I examined its intracellular localization incontrol HEK293T and MCF7 cells and in cells transiently transfected witha construct encoding fulllength CD74. Strikingly, in the transfectedcells, Scribble appeared to change its typical localization at theadherence junctions and translocate to the cytoplasm. This is shown inFIG. 2. In the stably transfected HEK293s cells, the protein did notchange localization as dramatically after 24 hours of induction, but itsimmunoreactivity increased and the CD74-expressing cells consistentlyshowed significantly higher fluorescence in confocal images (FIG. 3C).This increased immunoreactivity was reproduced in FACS experiments (FIG.3B) but not in Western blot analyses (FIG. 3A). To shed more light onthe underlying mechanisms, I then asked whether CD74 and Scribbleinteract and/or colocalize in the stably transfected cells. Binding ofCD74 to a particular part of Scribble might, for example, prevent theinteraction of Scribble with a third protein and effectively ensure thatthe epitope recognized by the anti-Scribble antibody is exposed anddetectable in immunofluorescence and FACS experiments. Indeed, in bothco-IP/Western blot and co-IP/MS experiments, CD74 and Scribblecopurified as shown in FIG. 4. I first performed co-IP/Western blotexperiments, in which CD74 was immunoprecipitated using an antibodyrecognizing its extracellular part. The immunoprecipitated proteins wereprobed with anti-Scribble antibody and a band with the sameelectrophoretic mobility as Sribble was detected only in the co-IP fromcells overexpressing CD74 but not from control uninduced cells (FIG.4A). To rule out any possibility that this result might have been due toa nonspecific binding or antibody cross-reactivity, I performedindependent co-IP/MS experiments. These were again designed around thequantitative SILAC technology; its implementation for proteininteraction analysis is described by Blagoev et al. [21] and tookadvantage of the high sensitivity and mass accuracy of the hybridLTQ/Orbitrap technology. To ensure quantitative precision and rule outfalse-positive results, the co-IP/MS experiments were performed twiceindependently and in the following manner: In the first experiment, Ilabeled one cell culture with heavy arginine and lysine and had anothercell culture grown on light amino acids. I then induced CD74 expressionfor 24 hours in the heavy-labeled culture but left the light-labeledculture uninduced. Then, CD74 was immunoprecipitated from both cellcultures under identical conditions and using equal total proteinamounts. The proteins immunoprecipitated from “heavy” and “light”cultures were mixed, separated by denaturing PAGE, digested withtrypsin, and analyzed by high-resolution LC-MS/MS. To increase thesensitivity of detection, I performed a mixed modedata-dependent/targeted analysis. This allowed a very precisequantitative assessment of the ability of CD74 to coimmunoprecipitateScribble. In the alternative labeling experiment, this procedure wasrepeated but in reverse: The light-labeled culture was induced withtetracycline, while the heavy-labeled sample was left uninduced. Theresults from these experiments are shown in FIG. 4B. In both assays,Scribble reporter peptides were only detected in the CD74 IP from theinduced samples but not from the uninduced samples. Thus, CD74 andScribble copurify, which suggests that the two proteins might interactphysically, either directly or through a third protein. If this is thecase and the interaction takes place in vivo, then subpopulations ofCD74 and Scribble molecules should also be seen at the same sites in thecells. I therefore asked whether the two proteins colocalize andperformed double-labeling immunofluorescence experiments to test thishypothesis. The results, illustrated in FIG. 4C, show that, indeed, thisis the case and portions of the pools of the two proteins clearlycolocalize in the CD74-overexpressing cells. In another independent lineof investigations, I transfected TetOCD74 HEK293 cells with a greenfluorescent protein (GFP)-tagged Scribble construct and asked whetherGFP-Scribble would change localization when the expression of CD74 isturned on by tetracycline. The results from these experiments areillustrated in FIG. 5. The GFP-Scribble reporter localized to thebasolateral parts of the membrane in the uninduced cells and was neverseen on the apical side of the cell. In contrast, when CD74 wasoverexpressed for 24 hours, GFPScribble clearly appeared at the apicalside of the cells. This was also seen in indirect immunofluorescenceexperiments, in which I stained endogenous Scribble with a monoclonalantibody as in the experiments presented in FIG. 4 and examined itslocalization by confocal microscopy.

In recent tumor proteomics study focusing on triple-negative breastcancer, I identified CD74 as frequently overexpressed in the lymphnode-metastatic tumors [5].

It was unexpectedly discovered that when CD74 is overexpressed incultured epithelial and cancer cells, the phosphorylation state ofseveral sites in the C-terminal part of the tumor suppressor proteinScribble changes significantly. The corresponding phosphopeptides weredetected and quantified by high-resolution mass spectrometry using SILAC-labeled cells. Altogether, 19 different Scribble phosphorylationsites were mapped and also quantified a large number of unmodifiedScribble peptides. This enabled statistical analysis that pinpointedfour phosphorylation sites as hotspots—phosphorylations that changesignificantly in response to CD74 overexpression. Three of these sitesconform to the canonical MAPKconsensus, which is intriguing as CD74 waspreviously implicated in an MAPK signaling: As a cellular receptor forthe cytokine macrophage inhibitory factor (MIF), CD74 was shown tointeract and activate the RAF/mitogen-activated protein kinase kinase(MEK)/extracellular signal-regulated kinase (ERK) cascade [6].Furthermore, Scribble localization changed and apparent immunoreactivityincreased in cells overexpressing CD74 (FIG. 2). Conceivably, therecould be at least three explanations for this increasedimmunoreactivity: 1) Scribble protein abundance might be upregulated inresponse to CD74 overexpression; 2) the epitope recognized by theanti-Scribble antibody could overlap with and be masked by theMAPK-dependent phosphorylations discussed above, which would mean thatoverexpression of CD74, by decreasing the phosphorylation on thesesites, would increase the immunoreactivity of Scribble; 3) the epitopeis masked by a protein that binds to it in the control cells, but thisinteraction is disrupted in CD74-overexpressing cells. The first modelis immediately disproved because the SILAC analysis showed nosignificant change in total Scribble after 24 hours of tetracyclinetreatment. A Western blot analysis confirmed this (FIG. 3A), although incells induced for longer periods of time Scribble abundance did decreasemoderately (FIG. 9). Thus, CD74 overexpression increased theimmunoreactivity of native Scribble but did not affect it in Westernblots where the protein is fully unfolded and denatured. The Westernblot results also disprove the second model: If increased Scribbleimmunoreactivity in the CD74-overexpressing cells was due to ahypophosphorylated epitope, it is likely that it would have shown up inthe Western blot results as well. Thus, the only valid model isexplanation 3, which assumes, for specific changes in the network ofprotein-protein interactions of Scribble, its immediate molecularmicroenvironment. This is consistent with the fact that Scribbleappeared to change localization when CD74 was overexpressed (FIGS. 2 and5).

Furthermore, when overexpressed CD74 was able to coimmunoprecipitateScribble and was seen to colocalize with a subset of Scribble molecules(FIG. 4).

Taken together, our results show that when overexpressed, CD74 engagesin a functional interaction with Scribble, which initially affects notonly the total abundance of Scribble but also the pattern of itsposttranslational modifications in the C-terminal part of the protein.This, by as yet to be elucidated mechanisms, causes the tumor suppressorprotein to shift its localization from the basolateral membrane and thesites of cell-to-cell contacts to the cytoplasm and the apical membrane.Apparently, this also leads to a down-regulation of Scribble in the longrun as the protein abundance decreased after 48 hours of induced CD74expression (see FIG. 9). Thus, when CD74 is overexpressed for aprolonged period of time, it appears to cause an overall decrease inScribble abundance. This is consistent with data from a large-scaleLC-MS/MS analysis of a collection of breast tumors I carried outrecently and will describe in a separate publication. In this data set,summarized in FIG. 10, CD74 and Scribble showed a clear negativecorrelation: The tumors with the highest CD74 abundance showed lowestScribble abundance and vice versa. These data further corroborate thelink between CD74 overexpression and Scribble deregulation establishedin our experiments with cell-based models and transient and stableinducible overexpression of CD74.

Scribble is a potential tumor suppressor and its deregulation andabnormal localization in breast tumors has been documented already [9].The protein plays a crucial role in the maintenance of epithelialpolarity [10, 22, 23]. It is known to interact with themitogen-activated protein kinases of the ERK family, apparentlydownregulating their activation and ability to migrate to the nucleus[24, 25]. As reported in the study of Nagasaka et al., in normalepithelial cells, Scribble is localized at the basolateral membrane andthis is required for its ability to inhibit G1-to-S transition [26].Here, I showed that overexpression of CD74, a frequently observedphenomenon in breast cancer, is a direct cause for deregulation ofScribble. This finding can explain why triple-negative breast tumorsoverexpressing CD74 tend to be more aggressive and with a heightenedmetastatic propensity. It also suggests that the pathway involved inthis mechanism could be a good target for developing rationale-basedtherapies and companion diagnostics for the treatment of triple-negativebreast cancer.

Example II Methods

1. Sample Preparation

Tumour tissue is collected as described previously [27] and kept frozenat −80° C. until needed for analysis. Membrane proteins are isolated bytissue permeabilization and detergent extraction as described in [27].The isolated membrane proteins are digested with trypsin and theresulting peptide sample is quantified by spectrophotometry using amicro cuvette to minimize sample loss.

2. Detection and Quantification of the Biomarkers

The biomarkers are detected as positively-charged peptide ions by liquidchromatography and mass spectrometry. The a mass spectrometer should becapable of tandem mass analysis. I used an LTQ/Orbitrap Velos but otherinstruments can also be used. Prior to analysis, a cocktail of internalstandards comprising stable isotope-labelled phosphorylated peptidesmight be added to the sample to be analysed. The internal standards havesequences identical to the Scribble peptides shown in Table 1, but areheavier by a precise number of mass units. This will allow preciseabsolute quantitation of the biomarker peptides. This type of analysiswill generate similar data to the ones reported in Metodieva et al(2013). Alternatively or in addition, a relative quantitation can beperformed, in which the intensity of the biomarker peptide ions, asmeasured by the mass spectrometer, would be normalized against theintensities of a panel of peptide ions generated by the ionization ofselect unmodified Scribble peptides.

Results

I have carried out model experiments with recombinant Scribble expressedin cultured human cells with the objective of confirming that the dataobtained by analysing endogenous Scribble in large-scale quantitativephosphoproteomics in cancer cell lines is indeed accurate. This is veryimportant as large-scale phosphoproteomics experiments can containmiss-assigned mass spectra, especially miss-assigned to phosphorylatedsequences. To rule out any possibility that some of the results couldhave been generated through such miss-assignment I expressedepitope-tagged Scribble in human kidney embryonic cells (HEK293). I thenaffinity-purified the recombinant Scribble using a monoclonal antibodyrecognizing the epitope tag and confirmed the detection of thephosphorylated peptides. Then the four phosphorylation sites, S1306,S1309, S1348, and S1448 were mutagenized individually to Alanine toprevent the phosphorylation in vivo and the affinity purificationexperiment was carried again with cells expressing each of the 4mutants. In each of these experiments only the peptides ionscorresponding to the phosphorylation sites that were not mutagenizedwere detected but there were no peptides ions corresponding to thephosphorylation on the sites that were changed to Alanine. These resultsfully confirmed that the peptide ions I am measuring are indeed the 5Scribble phosphopeptides listed in Table 1.

FIG. 11 illustrates the detection of one of the biomarkers inrecombinant epitope-tagged Scribble purified from HEK293 cells.Specifically, the detection of phosphorylated peptideQSPAS(ph)PPPLGGGAPVR (SEQ ID NO:15) derived from human Scribble protein.The phosphorylation site was mapped to the serine residue at position 5and is indicated with (ph) after the acceptor residue. The top trace istotal ion chromatogram (TIC). Below is the base peak chromatogram tracein red. The phosphorylated peptide is detected as doubly-charged ionwith a mass to charge ratio of 784.385. The extracted ion chromatogramfor this eptide is shown as a blue trace. The isotopic cluster of thispeptide ion is shown in the zoomed in high-resolution spectrum on thebottom. The unphosphorylated peptide was also detected as adoubly-charged ion with m/z of 744.402. Its extracted ion chromatogramis shown with a green trace and spectrum in the insert framed in blue.

TABLE 1 Scribble phosphopeptide biomarkers. The peptidesequences are shown with the phosphorylationsites indicated with (ph) after the acceptorresidue. The peptide charges, mass to chargeratios, mass and mass error in ppm are alsoshown. The mass to charge ratios and massesare as determined by the Orbitrap analyser at resolution 30,000. MassSEQ Modified Error ID  Sequence Charge m/z Mass (ppm) No. AFAAVPTSHPPED3 1140.208 3417.603 −0.28113 11 APAQPPTPGPAAS (ph)PEQLSFR MAESPCSPSGQQP3 988.7446 2963.212 −0.20162 12 PS(ph)PPS(ph) PDEIPANVK MAESPCSPSGQQP 3962.0892 2883.246 0.02382 13 PSPPS(ph) PDELPANVK MAESPCSPSGQQP 3962.0892 2883.246 −0.12338 14 PS(ph)PPSPDEL PANVK QSPAS(ph)PPPL 2784.3851 1566.756 0.28104 15 GGGAPVR

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1. A method of diagnosing cancer in a patient, the method comprisingdetecting the phosphorylation status of a Scribble protein, a fragmentor variant thereof, wherein said phosphorylation status is indicative ofcancer.
 2. A method of claim 1, comprising detecting the phosphorylationstatus of one or more residues of a Scribble protein or fragment orvariant thereof.
 3. The method of claim 1, comprising detecting thephosphorylation status of at least one of the following residues S1306,S1309, S1348 and S1448 or a combination thereof.
 4. The method of claim1, wherein the patient is a cancer patient or is at risk of developingcancer.
 5. The method of claim 4, wherein the patient's cancer is anepithelial cancer.
 6. The method of claim 5, wherein the patient'scancer is breast, pancreas, bone, liver, stomach, lung, colorectal,bladder, prostate or ovarian cancer.
 7. The method of claim 6, whereinthe cancer is breast cancer and wherein the breast cancer tumour doesnot express at least one marker selected from the group consisting ofoestrogen receptor (ER), progesterone receptor (PgR) and the ErbB2receptor.
 8. The method of claim 1, wherein detecting thephosphorylation status comprises obtaining a sample from said patientand contacting the sample with at least one antibody that is capable ofspecifically binding phosphorylated or unphosphorylated residues of aScribble protein, fragment or variant thereof.
 9. The method of claim 1,wherein detecting the phosphorylation status comprises obtaining asample from said patient and detecting the phosphorylation status bymass spectrometry.
 10. The method of claim 1, further comprisingdetecting the expression of one or more other biomarkers.
 11. A methodfor evaluating the prognosis of cancer, the method comprising detectingthe phosphorylation status of a Scribble protein, a fragment or variantthereof, wherein the phosphorylation status is indicative of prognosis.12. A method for detecting the phosphorylation status of a Scribbleprotein with SEQ ID NO: 1, a fragment or variant thereof, the methodcomprising: obtaining a sample from a patient and contacting the samplewith at least one antibody that is capable of specifically bindingphosphorylated or unphosphorylated residues S1306, S1309, S1348 andS1448 or a combination thereof in the Scribble protein, fragment orvariant thereof.
 13. The method of claim 12, wherein the method isperformed in conjunction with at least one of the following: evaluatingcancer prognosis, developing a cancer treatment plan, assessing theefficiency of cancer treatment and the likelihood of metastases.
 14. Anantibody capable of selectively binding to at least one phosphorylatedor unphosphorylated residue in a Scribble protein with SEQ ID NO: 1, orfragment or variant thereof, selected from residues S1306, S1309, S1348and S1448 or a combination thereof.
 15. A kit for use in the method ofclaim 1 comprising at least one antibody capable of selectively bindingto at least one phosphorylated or unphosphorylated residue in a Scribbleprotein with SEQ ID NO: 1, or fragment or variant thereof, selected fromresidues S1306, S1309, S1348 and S1448 or a combination thereof, whereinsaid kit further comprises agents for the detection of the at least oneantibody binding to said phosphorylated residues in Scribble.
 16. Thekit of claim 15, wherein said kit further comprises instructions foruse.
 17. A kit for use in the method of claim 11 comprising at least oneantibody capable of selectively binding to at least one phosphorylatedor unphosphorylated residue in a Scribble protein with SEQ ID NO: 1, orfragment or variant thereof, selected from residues S1306, S1309, S1348and S1448 or a combination thereof, wherein said kit further comprisesagents for the detection of the at least one antibody binding to saidphosphorylated residues in Scribble.
 18. The kit of claim 17, whereinsaid kit further comprises instructions for use.
 19. A kit for use inthe method of claim 12 comprising at least one antibody capable ofselectively binding to at least one phosphorylated or unphosphorylatedresidue in a Scribble protein with SEQ ID NO: 1, or fragment or variantthereof, selected from residues S1306, S1309, S1348 and S1448 or acombination thereof, wherein said kit further comprises agents for thedetection of the at least one antibody binding to said phosphorylatedresidues in Scribble.
 20. The kit of claim 19, wherein said kit furthercomprises instructions for use.